--- title: Saving water and energy at home — how Mova does on the tests · World description: Lesson 89 of the world course of Mova's primary school: 5 of 13 tests right, exam 1 of 4, every question with the options, the student's choice, the right answer and why it chose. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/school-run/world/89-saving-water-and-energy/) [home](https://md.mova.elamur.ai/free/en/) / [at school](https://md.mova.elamur.ai/free/en/school-run/) / [World](https://md.mova.elamur.ai/free/en/school-run/world/) / 89 # Saving water and energy at home **Tests:** 5 of 13 right · **Exam:** 1 of 4 right · **Kind:** ★ · **Understood:** 11 of 17 · **Run:** 2026-10-18, commit `f3c23ea72` Lesson 89 of the world course of Mova's primary school, as Mova's small model took its tests: it had read this lesson and the ones before it and learned from their exercises. Each test shows the options in the order the student saw them, its choice, the right answer, the score of every option and why it chose. The lesson itself, sentence by sentence with trees and pragmatics: [the lesson in the corpora](https://md.mova.elamur.ai/free/en/corpora/school/world/89-saving-water-and-energy/). Every question of this lesson and each of its options parsed by Mova, with trees and pragmatics: [the lesson's questions in the corpora](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/). ### Test 1 · ★ · wrong ✗ {#t1} A family takes baths every day and then switches to short showers. What two things do they save? - **1.** Only the soap they use — no support - **2.** Only the cold water — no support - **3.** Nothing, because showers use more water — **← Mova's choice** · score 12 - **4.** Water and the energy to heat it — **✓ the right answer** · no support **Why:** It took the question to ask what it is done to. It chose option 3 with score 12, the only option with support. Its support: lesson 89, line 11: «A short shower usually uses much less water than a full bath.», reached through the option's own match among the sentences about the question's things. What matched: the same action «use» (+5); it fills the role the question asks for (+3); the same doer «short shower» (+2); the same thing acted on «less water» (+2). The right option, 4, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/t1/) ### Test 2 · ★ · wrong ✗ {#t2} Which is true? - **1.** Tap water comes to us without using any energy — **← Mova's choice** · no support - **2.** Saving water helps save energy as well — **✓ the right answer** · no support - **3.** A dripping tap wastes only a cupful a year — no support - **4.** Most water on Earth is fresh and drinkable — no support **Why:** Nothing it remembers matched the question, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/t2/) ### Test 3 · ★ · wrong ✗ {#t3} Two identical houses are heated equally. One has a thick insulated roof. What happens on a cold night? - **1.** The house without insulation stays warmer — **← Mova's choice** · no support - **2.** Both houses lose heat at exactly the same rate — no support - **3.** The insulated house gets colder faster — no support - **4.** The insulated house stays warmer for longer — **✓ the right answer** · no support **Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/t3/) ### Test 4 · ★ · right ✓ {#t4} Tom leaves his game console on standby all year. What happens? - **1.** It stores extra energy for later games — no support - **2.** It uses electricity all year even when not played — **← Mova's choice** · **✓ the right answer** · score 5 - **3.** It uses no electricity because the screen is dark — score 5 - **4.** It makes the console last for ever — score 2 **Why:** It took the question to ask what happens next. It chose option 2 with score 5, tied with another option at 5 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 89, line 15: «Many devices still use electricity on standby when they look switched off.», reached through the option's own match among the sentences about the question's things. What matched: the same action «use» (+3); the same thing acted on «electricity» (+3). Against it: a different doer (counts against) (-1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/t4/) ### Test 5 · ★ · wrong ✗ {#t5} A country has a long dry summer. Why is wasting water a bigger problem then? - **1.** Plants stop needing water in summer — **← Mova's choice** · no support - **2.** The sea becomes fresh in summer — no support - **3.** Pipes freeze and burst in the heat — no support - **4.** Less fresh water is left in rivers and storage lakes — **✓ the right answer** · no support **Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/t5/) ### Test 6 · ★ · wrong ✗ {#t6} Which change in a school would save the most energy in a cold country? - **1.** Turning off one lamp for a minute — **← Mova's choice** · no support - **2.** Using pencils instead of pens — no support - **3.** Insulating the walls and roof — **✓ the right answer** · no support - **4.** Opening the windows in winter — no support **Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/t6/) ### Test 7 · ★ · wrong ✗ {#t7} Mia says, "Water is free because it falls from the sky." What is she missing? - **1.** Rain water never reaches rivers — no support - **2.** Rain is too salty to fall on cities — no support - **3.** Taps make the water themselves — **← Mova's choice** · score 10 - **4.** Cleaning and pumping it to taps costs energy and money — **✓ the right answer** · score 3 **Why:** It took the question to ask what it is done to. It chose option 3 with score 10, against 3 for the next best. Its support: lesson 20, line 4: «Salt is spread on icy roads because salty water freezes at a lower temperature than pure water; the salt dissolves in the thin wet layer on the ice and makes i…», reached through the option's own match among the sentences about the question's things. What matched: the same action «make» (+5); it fills the role the question asks for (+3); the same thing acted on «water» (+2). The right option, 4, scored 3. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/t7/) ### Test 8 · ★ · right ✓ {#t8} Why can wasting a meal also waste water? - **1.** Food turns into sea water once it is in the bin — no support - **2.** Growing the food needed a lot of water — **← Mova's choice** · **✓ the right answer** · score 4 - **3.** Plates must be washed in the river — no support - **4.** Cooking food creates new water — score 3 **Why:** It took the question to ask why something happens (its cause). It chose option 2 with score 4, against 3 for the next best. Its support: lesson 89, line 16: «Growing food and making clothes also uses a great deal of water, so wasting food wastes water too.», reached through the same lesson line as the sentence the question matched. What matched: the same action «grow» (+3); the same thing acted on «food» (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/t8/) ### Test 9 · ★ · wrong ✗ {#t9} A school replaces 100 old bulbs with LED bulbs. What happens? - **1.** The rooms stay as bright but more electricity is used — **← Mova's choice** · no support - **2.** The bulbs stop needing electricity — no support - **3.** The rooms stay as bright but less electricity is used — **✓ the right answer** · no support - **4.** The rooms get darker and less electricity is used — no support **Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/t9/) ### Test 10 · ★ · wrong ✗ {#t10} shower or bath, which saves more water - **1.** A long shower uses less than any bath — score 4 - **2.** They always use exactly the same water — score 6 - **3.** A full bath usually uses much less water than a shower — **← Mova's choice** · score 9 - **4.** A short shower usually uses much less water — **✓ the right answer** · score 8 **Why:** It took the question to ask which statement is true. It chose option 3 with score 9, against 8 for the next best. Its support: lesson 89, line 11: «A short shower usually uses much less water than a full bath.», reached through the remembered sentence the question matched. What matched: the same action «use» (+4); the same circumstance (+4); the same property (+2); the same thing acted on «less water» (+1). Against it: a different doer (counts against) (-2). The right option, 4, scored 8. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/t10/) ### Test 11 · ★ · right ✓ {#t11} telly's off but the little light's still on, is it using power - **1.** Yes, but only at night — no support - **2.** No, it uses no power at all when the screen is off — no support - **3.** Yes, many devices use electricity on standby — **← Mova's choice** · **✓ the right answer** · score 10 - **4.** No, the light makes its own power — no support **Why:** It took the question to ask which statement is true. It chose option 3 with score 10, the only option with support. Its support: lesson 89, line 15: «Many devices still use electricity on standby when they look switched off.», reached through the remembered sentence the question matched. What matched: the same action «use» (+4); the same place «standby» (+4); the same doer «many devices» (+1); the same thing acted on «electricity» (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/t11/) ### Test 12 · ★ · right ✓ {#t12} Ava says saving water has nothing to do with saving energy. true? - **1.** No, pumping, cleaning and heating water all use energy — **← Mova's choice** · **✓ the right answer** · score 5 - **2.** Yes, water and energy are not linked at all — no support - **3.** Yes, water comes to homes with no energy — score 5 - **4.** No, saving energy wastes water instead — score 5 **Why:** It took the question to ask which statement is true. It chose option 1 with score 5, tied with another option at 5 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 89, line 9: «Pumping and cleaning water uses energy, so saving water also saves energy.», reached through the same lesson line as the sentence the question matched. What matched: the same action «use» (+3); the same thing acted on «energy» (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/t12/) ### Test 13 · ★ · right ✓ {#t13} my cousin reckons a dripping tap only wastes a few drops. right? - **1.** No, a dripping tap can waste thousands of litres in a year — **← Mova's choice** · **✓ the right answer** · score 8 - **2.** No, a dripping tap saves water — no support - **3.** Yes, it wastes less than a cup a year — score 5 - **4.** Yes, the drops are too small to matter — no support **Why:** It took the question to ask which statement is true. It chose option 1 with score 8, against 5 for the next best. Its support: lesson 89, line 12: «A dripping tap can waste thousands of litres of water in a year.», reached through the remembered sentence the question matched. What matched: the same action «waste» (+4); the same property (+2); the same doer «dripping tap» (+1); the same thing acted on «thousands» (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/t13/) ### Exam question 1 · formal language · right ✓ {#e1} Which of the following statements most accurately characterises the reason for which saving hot water saves the most energy? - **1.** Hot water evaporates more slowly than cold — score 8 - **2.** Cold water requires no cleaning — score 8 - **3.** Heating water uses a great deal of energy — **← Mova's choice** · **✓ the right answer** · score 12 - **4.** Hot water is more costly to pump than cold — score 9 **Why:** It took the question to ask who or what does it. It chose option 3 with score 12, against 9 for the next best. Its support: lesson 89, line 10: «Heating water uses a lot of energy, so saving hot water saves the most.», reached through the same lesson line as the sentence the question matched. What matched: it fills the role the question asks for (+5); the same doer «heating water» (+4); the same action «use» (+3). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/e1/) ### Exam question 2 · formal language · wrong ✗ {#e2} Identify the bulb which gives equal light with far less electricity. - **1.** An old filament bulb — **← Mova's choice** · score 3 - **2.** A coloured glass bulb — no support - **3.** An LED bulb — **✓ the right answer** · no support - **4.** A bulb of greater power — no support **Why:** It took the question to ask which statement is true. It chose option 1 with score 3, the only option with support. Its support: lesson 89, line 14: «An LED bulb gives the same light as an old filament bulb with far less electricity.», reached through the remembered sentence the question matched. What matched: the same property (+2); the same doer «led bulb» (+1). The right option, 3, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/e2/) ### Exam question 3 · formal language · wrong ✗ {#e3} Select the response that is consistent with the established facts concerning devices left on standby. - **1.** They use no electricity whatsoever — **← Mova's choice** · score 6 - **2.** Many still use electricity when they look switched off — **✓ the right answer** · score 5 - **3.** They generate electricity for the home — score 1 - **4.** They use electricity only during the day — score 6 **Why:** It took the question to ask which statement is true. It chose option 1 with score 6, tied with another option at 6 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 89, line 15: «Many devices still use electricity on standby when they look switched off.», reached through the remembered sentence the question matched. What matched: the same action «use» (+4); the same doer «many devices» (+1); the same thing acted on «electricity» (+1). The right option, 2, scored 5. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/e3/) ### Exam question 4 · formal language · wrong ✗ {#e4} Ascertain the function of insulation in the roof and walls of a house. - **1.** It cools the house by admitting wind — **← Mova's choice** · no support - **2.** It draws heat into the house from the ground — no support - **3.** It keeps heat inside the house in winter — **✓ the right answer** · no support - **4.** It increases the loss of heat in winter — no support **Why:** Nothing it remembers matched the question, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/world/89-saving-water-and-energy/e4/) - ← previous: [88. Recycling, waste and plastic](https://md.mova.elamur.ai/free/en/school-run/world/88-recycling-waste-plastic/) - next →: [90. Measuring the world — length, mass, time and tem…](https://md.mova.elamur.ai/free/en/school-run/world/90-measuring-the-world/) - ↑ back to [World](https://md.mova.elamur.ai/free/en/school-run/world/)