The rules of our school don’t allow _______ at school. That is to say, nobody is allowed _______ here.
| A．to smoke; to | B．smoking; smoking | C．to smoke; smoking | D．smoking; to smoke |
For our middle school students, some courses are compulsory, while others are ________.
| A．flexible | B．optional | C．impressive | D．significant |
Someone is ringing the doorbell. Go and see ___________.
| A．who is he | B．who he is | C．who is it | D．who it is |
One ought __________ for what one hasn’t done.
| A．not to be punished | B．to not be punished |
| C．to not punish | D．not be punished |
Luckily good things _________ here to save local wildlife.
| A．are doing | B．are being done |
| C．had been done | D．will do |
The earth became so violent that it was not clear_________ the shape would last or not.
| A．if | B．how | C．whether | D．why |