It is reported that two young officer gave their life in solving the incident. Don't you think the _______ is too great?
| A．value |
| B．cost |
| C．risk |
| D．challenge |
The Smiths have gone to New York for their holiday, with an old servant ____ their house.
| A．looking after | B．look after | C．having looked after | D．looked after |
I was about to go to bed _____ one of my old classmates made a call to me.
| A．that | B．as | C．while | D．when |
Only those ____knew well could be let in.
| A．who | B．which | C．what | D．he |
The criminal, as well as some ______ people, was arrested by the police yesterday.
| A．relevant | B．skilled | C．evil | D．lucky |
____ with the size of the whole earth, the highest mountain doesn’t seem high at all.
| A．To compare | B．while comparing | C．It comparing | D．when compared |