——There must be a dozen pens in this house but I can never find one when I need one.
——Keep looking. is sure to turn up.
| A．One | B．It | C．That | D．This |
The chairman thought _____ necessary to invite Professor Smith to speak at the meeting.
| A．that | B．it | C．this | D．him |
She ______his number in the phone book to make sure that she had got it right.
| A．looked up | B．looked for | C．picked out | D．picked up |
You said boys were cleverer than girls. That is _______ I disagree.
| A．what | B．where | C．which | D．why |
With the rapid growth of population, the city______ in all directions in the past five years.
| A．spreads | B．has spread | C．spread | D．had spread |
The bell______ the end o f the period rang and we had to stop our discussion.
| A．indicating | B．indicated | C．to be indicated | D．being indicated |