-Did you visit the museum last week?
-No, we __________，but we spent too much time shopping.
| A．could have |
| B．could |
| C．must have |
| D．must |
He has three brothers, ________ is a doctor．
| A．all of them | B．all of whom | C．none of whom | D．both of them |
He never reads anything _______ is not worth reading．
| A．as | B．which | C．who | D．that |
―When was the house built?
―It was built in 1949 _______ the PRC was founded．
| A．which | B．that | C．what | D．when |
________ is known to everybody, the moon travels round the earth once every month．
| A．It | B．As | C．That | D．What |
This is Mr．Smith, ________ I think has something interesting to tell you．
| A．who | B．whom | C．that | D．/ |