—Have you graduated from Shandong University?
—Yes.I________there for 4 years.
| A．studied | B．have studied |
| C．had studied | D．have been studying |
The machine is easy to _______if you follow the instructions.
| A．be operated | B．operate | C．be operated on | D．operate on |
_____who had arrested him three times for drug-taking.
| A．Before George did the policeman stand | B．Before George the policeman stood |
| C．Before the policeman stood George | D．Before George stood the policeman |
To help Tom improve his English, I_______ that he take some online courses.
| A．recommend | B．acknowledge | C．abandon | D．declare |
After retirement, she _____ herself in _______the poor children.
| A．occupied, helping | B．occupied, to help |
| C．devoted, to help | D．devoted, helping |
Preparations have been ______for the project and it can be started at any moment.
| A．contradicted | B．approved | C．made | D．purchased |