My mother thought she ________ the door, but in fact she had forgotten ________ it．

A．had locked; to lock

B．locked; locking

C．locked; to locking

D．had locked; locking

－I had a chance to be sent to Africa to attend a meeting on the environment protection．

－Well，would you please tell me about your ________ there?

A．experience

B．experiences

C．practice

D．incidents

Zheng He’s first stop was in ________ is today a part of Vietnam．

A．where

B．which

C．that

D．what

There were two fantastic photos for the book, ________ was chosen as the front cover．

A．one of them

B．both of them

C．one of which

D．all of which

A healthy food includes all types of food, ________ no single food or food group can provide all the nutrients our body needs．

A．if

B．when

C．which

D．because

I had to tell you the truth, ________?

A．hadn’t I

B．wouldn’t I

C．didn’t I

D．shouldn’t I

The experiment，________ will soon be announced，was done by my colleagues．

A．whose results

B．the results on which

C．at which the results

D．of whose results

If you ________ to take this attitude，we’ll have to ask you to leave．

A．insist

B．keep

C．choose

D．stick

－What ________ her liver to fail?

－Weight-loss pills．

A．made

B．had

C．caused

D．affected

－I bet Jonna will win the badminton match．

－So do I，no one is her ________．

A．match

B．fit

C．opposite

D．suit