global warming

Algae are simple plants that grow in or near water and do not have ordinary leaves or roots. They can be very small like green spots or very large like seaweed found in the ocean.

An amphibian is a type of animal that can live both on land and in water. Most amphibians, like frogs and salamanders, start their lives in the water and move to land as they grow older.

An asteroid is a large rock that travels through space and orbits the sun. It is much smaller than a planet and is mostly made of rock and metal.

Astronomy is the scientific study of stars, planets, and everything else in space. It is the branch of science that looks at how the universe works outside of Earth's atmosphere.

Atmospheric pressure is the weight of the air in the sky pressing down on the Earth. It changes depending on the weather and how high you are above the sea.

털이 많고 크고 힘센 동물을 말해요.

낙타는 등에 하나 또는 두 개의 혹이 있는 큰 동물입니다.

위장은 주변 환경과 비슷하게 보여서 몸을 숨기는 방법이에요. 눈에 잘 띄지 않게 해서 위험으로부터 자신을 보호하는 거죠.

나무들의 가지와 잎이 모여서 만들어진 숲의 가장 윗부분을 말해.

협곡은 아주 가파른 절벽이 있는 깊은 골짜기예요. 보통 강물이 흐르면서 오랜 시간 동안 땅을 깎아 만들어지죠.