It is ||||| who answered the call.
A. me
B. him
C. I
D. us
老师，你好。这道题该怎么样选择？另外，题中who后面的动词假如改成一般目前时的动词时，又该怎么样选择？
When drinking from a well, one mustn’t forget ||||| who dug it.
A. them
A. these
B. that
C. those
在这道题里，who后用了dug，这个时候又该怎么样选择？
It is ||C|| who answered the call.
A. me
B. him
C. I
D. us
When drinking from a well, one mustn’t forget ||those||| who dug it.
A. them
A. these
B. that
C. those
