如下选择题应该选项什么?请注明为什么,谢谢。
一,these young trees require ____carefully。
a。looking after
b。to look after
c,look after
d,looking for
二,Donn't get off the bus until it___。
a,Has stopped
b,stopped
c,will stop
d,shall stop
三,“is the radio bothering you?"
"it certainly is 。i'd like it ___off"
a,turning
b,to turn
c,turned。
d,turns
。