The door is low, so ______ your head when you go in.
| A．attend | B．guard | C．protect | D．mind |
The classroom is big enough , but we’ll have to move if we have more students.
| A．for the moment | B．on the moment | C．in a moment | D．for a moment |
We shall go ____ you are ready.
| A．while | B．as soon as | C．as | D．since |
Mark was a student at this university from 1999 to 2003, ____ , he studied very hard and was made Chairman of the Students' Union.
| A．during which time | B．for which time | C．during whose time | D．by that time |
It has not been decided ____ they will leave.
| A．why | B．when | C．which | D．what |
The accident is reported to have occurred __________ the first Sunday in February.
| A．at | B．on | C．in | D．to |