Question

7．_____ of my parents is poor-educated,they both left school

Answer 1

C

all是指三个或三个以上,而both是指两个；

both of两者都

Both of them are students.他们俩都是学生.

all of三个或在三个以上都

All of us are going to see the game.我们都要去看比赛.

either of (两者其一)

neither of(两者都不)

这两个后＋单数

both of (两者都),后＋复数

all of (三者或三者以上都是)

这道题因为 is poor-educated,如果Is改成are的话肯定选A,但是是Is,只能选C了.