In face of difficulties the climbers ______ in the hope of reaching the top before dark.
| A．insisted on | B．looked up | C．turned away | D．kept on |
After three days’ waiting, there was a little doubt in Jake’s mind______ the police could find his lost car.
| A．how | B．that | C．where | D．whether |
______ your opinions are worth considering, the committee finds it unwise to place too much importance on them.
| A．As | B．Since | C．If | D．While |
He is confident, ______, in my opinion, is most important in modern society.
| A．who | B．that | C．which | D．what |
The team, ______ to climb the world’s second tallest mountain twice, finally decided to give up.
| A．having attempted | B．attempting |
| C．attempted | D．to attempt |
I ______ Peter with his work, but I had a lot of things to do myself.
| A．must have helped | B．should have helped |
| C．needn’t have helped | D．can’t have helped |