The teachers are doing what they _____ their stuaits.
| A．can to teach | B．can teach | C．can teaching | D．can to teaching |
Comrade Li Dazhao, _____ librarian of Beijing University, was one of the founders of the Chinese Communist Party.
| A．sometimes | B．sometime | C．some time | D．some times |
The open university was started in order to help those who _____ having a university education when they were young.
| A．stopped | B．failed | C．missed | D．ceased |
He has left his book here on _____, so that you can read it.
| A．purpose | B．intention | C．aim | D．meaning |
I remember her face but I cannot _____ where I met her.
| A．recall | B．remind | C．remember | D．remark |
It is clear that the whole world is passing through a social revolution in which a central _____ must be taken by scientists and technologists.
| A．process | B．attention | C．measure | D．part |