⑴Are you Mike? ____
⑵Good afternoon, Miss Li. ____
⑶This is my brother, Tim. ____
⑷She is my sister, Yang Ling.____
⑸Good evening. ____ A. Hello, Yang Ling.B. No, I'm not.C. Good evening.D. Hello, Tim.E. Good afternoon, class.
假如我们把笔尖看作一个点,当笔尖在纸上移动时,就能画出线,说明了____ .
呼吸时,氧气由肺泡进入血液的原因是( )
bear