all_____is needed is fresh airA the thing B that C what D wichA the thing B thatC what D wich

问题描述:

all_____is needed is fresh airA the thing B that C what D wich
A the thing B that
C what D wich

all that=what
选B

d

选that啊,定语从句,
A 不对因为从句中all应作主语,所以必须有关系代词
C 不对因为what不能引导定语从句
D不对因为定语从句中which不能代 all

A

B all 充当先行词,因为是不定代词,所以关系词用that来引导定语从句.
all that = what

B