It is requested that visitors ________ photos in the museum.
| A．wouldn’t take | B．will not take |
| C．not to take | D．not take |
After the bell rings，which indicates the ending of the exam，you_____stay where you are until all your papers are collected．
| A．shall | B．would | C．will | D．can |
—You were not listening；what troubled you?
—I my coming math exam．
| A．am thinking about | B．was thinking about | C．had thought about | D．will think about |
I am amazed at someone so rich _____ difficulty in paying what he owes you.
| A．as to have | B．who has no | C．that he has no | D．having |
It doesn’t matter how much loss we have suffered; just avoid _____ the mistake again.
| A．to make | B．being made | C．having made | D．making |
Just as sound travels through the air in waves, electricity travels through the air in ______ radio waves.
| A．what is called | B．which is called | C．what it is called | D．which it is called |