Our research has focused on a drug which is so _____ as to be able to change brain chemistry.
| A．powerful | B．influential | C．monstrous | D．vigorous |
The patient was in bad need of operation but there was no guarantee(保证) that she would survive the anaesthetic (麻醉剂), which made the doctors on the horn of a __________.
| A．process | B．arrangement | C．ceremony | D．dilemma |
You _____ get the machine repaired this week. I won’t need it until next month.
| A．mustn’t | B．needn’t | C．shouldn’t | D．can’t |
Our manager never fails to answer a phone call ______ she is very busy.
| A．since | B．once | C．even if | D．so that |
Because of the lack of funds, the tunnel project has already fallen behind ________.
| A．situation | B．speed | C．insurance | D．schedule |
The book is rather highly priced, but so well worth ______ that it should be begged or borrowed rather than missed.
| A．to read | B．to be read | C．reading | D．being read |