The number 5.12 is a special number,__ ,I think, that will be remembered by Chinese people forever.
| A．what | B．it | C．which | D．one |
Time should be made full use of _________ ourselves.
| A．improving | B．to improve | C．for improving | D．improve |
Electricity ,like other forms of_________ ,has greatly increased in price.
| A．strength | B．force | C．power | D．energy |
In the good care of the nurses, the boy is _________ recovering from his disease.
| A．quietly | B．actually | C．frequently | D．gradually |
Ladies and gentlemen, please fasten your seat belts. The plane ________.
| A．takes off | B．has taken off | C．is taking off | D．took off |
The chairman thought ________ necessary to invite Professor Smith to speak at the meeting.
| A．hat | B．it | C．this | D．him |