Tetravalelent
四价染色体
🗣️ 情景例句
Sometimes he's very sad.
他有时很忧悒。
I slipped on the stairs and fell down.I broke my leg.
我在楼梯上滑倒了并且掉下来我弄断了腿的。
A child ran into the street and knocked her off her bicycle.
一个孩子冲上马路，把她从车上撞了下来。