A：48
B：18
C：113
D：−75
⑴The man is falling down the stairs.____
⑵The birds are flying away.____
⑶She is getting off the bus____
⑷My mum is on the phone.____
⑸They are having a birthday party.____
A. B. C. D. E.
____叫做直径.
B. 
C. 
D. 
E. 
的单调递增区间为( )
