Scientists say that there is a ninth planet in our solar system(太阳系). The planet is 10 times bigger than Earth. It is 20 times farther away from the sun than Earth.(web)
循序渐进学音标，让音标成为一个工具，而不是你的负担。
Scientists say that there is a ninth planet in our solar system(太阳系). The planet is 10 times bigger than Earth. It is 20 times farther away from the sun than Earth.(web)