--- title: Fish, frogs and reptiles — a lesson of Mova's school · trees and pragmatics description: «Fish, frogs and reptiles», a lesson of the world course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: A fish takes in water through its mouth and pushes it out over its gills, where the blood picks up the oxygen dissolved in the water. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [World](https://md.mova.elamur.ai/free/en/corpora/school/world/) / Fish, frogs and reptiles # Fish, frogs and reptiles Lesson 74 of the world course of Mova's primary school: 21 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/world/74-fish-frogs-reptiles/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/0/) — A fish takes in water through its mouth and pushes it out over its gills, where the blood picks up the oxygen dissolved in the water. - [1](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/1/) — Its tail fin drives it forward, and its other fins steer and keep it upright. - [2](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/2/) — Many fish have a swim bladder, a bag of gas inside the body; by changing how much gas is in it, the fish can float at any depth without sinking or rising. - [3](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/3/) — A line of special cells along each side, the lateral line, feels the smallest movements in the water. - [4](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/4/) — Frogs and other amphibians have thin, moist skin, and they can take in some oxygen through it, so they must keep it damp; their eggs have no shell and dry out in air, so they are laid in water or in damp places. - [5](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/5/) — Reptiles have dry, scaly skin that keeps water in, and their eggs have a tough shell, so they can live far from water, even in deserts. - [7](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/7/) — For example, a lizard basks on a sunny rock in the morning to warm up and hides in the shade at noon, and because it does not burn food for heat, it may need only a tiny part of the food a mouse of the same size eats. - [8](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/8/) — Fish take oxygen from the water with their gills. - [9](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/9/) — A fish's tail fin pushes it forward, and its other fins steer and balance it. - [10](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/10/) — Many fish have a swim bladder filled with gas that lets them float at one depth. - [11](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/11/) — The lateral line along a fish's side feels movements in the water. - [12](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/12/) — A shark's skeleton is made of cartilage, the bendy material in our ears and nose, not bone. - [13](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/13/) — A shark has no swim bladder, so it keeps swimming to stay up, and its light, bendy skeleton helps it. - [14](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/14/) — A frog can take in some oxygen through its thin, moist skin. - [15](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/15/) — Because their skin is thin, frogs are easily harmed by polluted water. - [16](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/16/) — Many frogs catch insects with a long, sticky tongue. - [17](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/17/) — Amphibian eggs have no shell, so they are laid in water or damp places. - [18](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/18/) — Reptiles' dry, scaly skin keeps water in their bodies, so many can live in deserts. - [19](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/19/) — A snake flicks its tongue to pick up smells from the air. - [20](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/20/) — Snakes shed their skin as they grow, often in one piece. - [21](https://md.mova.elamur.ai/free/en/corpora/school/world/74-fish-frogs-reptiles/21/) — Animals that get their warmth from their surroundings need much less food than mammals and birds of the same size. - ← previous: [Birds: feathers, nests and flight](https://md.mova.elamur.ai/free/en/corpora/school/world/73-birds-feathers-nests-flight/) - next →: [Mammals and how they care for their young](https://md.mova.elamur.ai/free/en/corpora/school/world/75-mammals-and-their-young/) - ↑ back to [World](https://md.mova.elamur.ai/free/en/corpora/school/world/)