Only when __________________ permission _______________ allowed to enter the lab.
| A．a teacher has given; are the students | B．has a teacher given; are the students. |
| C．has a teacher given; the students are | D．a teacher has given; the students are |
The doctor will be free ___.
| A．10 minutes later | B．after 10 minutes | C．in 10 minutes | D．10 minutes |
__ is known to everybody, the moon travels round the earth every month.
| A．It | B．As | C．That | D．Which |
---I drove to Zhuhai for the air show last week.---Is that ___ you had a few days off?
| A．why | B．when | C．what | D．where |
What the doctor really doubts is ___ my mother will recover from the serious disease soon.
| A．when | B．how | C．whether | D．why |
The number of the employees has grown from 1000 to 1200.This means it has increased ___20 percent.
| A．by | B．at | C．to | D．with |