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
The professor, ________ his assistants, _______ conducting the experiment.
A．in addition, is B．as well, is
C．in addition to, are D．as well as, is
