He has ____________ himself to be innocent (无罪的).
| A．checked | B．realized | C．confirmed | D．showed |
Honesty is a basic element in friendsmaking and that is ________ it requires to keep everlasting friendship.
| A．how | B．which | C．whether | D．what |
I travel to the Binhai New Area by light railway every day，________ do many businessmen who live in downtown Tianjin.
| A．as | B．which | C．when | D．though |
A person ________ email account is full won't be able to send or receive any emails.
| A．who | B．whom | C．whose | D．whoever |
She'll never forget her stay there ________ she found her son who had gone missing two years before.
| A．that | B．which | C．where | D．when |
Gun control is a subject ________ Americans have argued for a long time.
| A．of which | B．with which |
| C．about which | D．into which |