从生命活动的角度理解,人体的结构层次为( )
⑴____ A. grade B. able C. skate D. any
⑵____ A. egg B. me C. went D. tell
⑶____ A. rich B. sister C. swim D. write
⑷____ A. idea B. Korea C. real D. great
⑸____ A. school B. machine C. chemical D. ache