____ enters the computer rooms should take off his shoes in order to keep them clean enough.
| A．Who | B．Whoever | C．What | D．Whatever |
They arrived at a farmhouse，in front of ________ sat a small boy.
| A．whom | B．who | C．which | D．that |
The pen ________ he is writing is mine.
| A．with which | B．in which |
| C．on which | D．by which |
Can you lend me the book ________ the other day?
| A．about which you talked | B．which you talked |
| C．about that you talked | D．that you talked |
At the party，John made up a joke，________ people burst out laughing.
| A．on which | B．by which | C．at which | D．from which |
That is the day ________ I'll never forget.
| A．which | B．on which | C．in which | D．when |