It’s really a great pity that the great writer died ____ his works unfinished.

 It is hoped that there will be ____ time in the future when ____ man can defeat cancer.

 Scientists warn us _____ the need to keep an eye ____ the greenhouse effect.

 The old temple, which ______ to the 17^th century, needs to be repaired.

 ---Who do you think should ____ the responsibility for white pollution?

--- Both the producer and the consumer.

 I would rather you _____ the truth now instead of afterwards.

 The police came here in the hope ___ they could learn about the cause of the traffic accident.

 Her failure in the experiment suggested that she ______ the professor’s instructions.

The general spoke highly of such _____ as honesty, loyalty and bravery shown by the soldiers.

 In order to complete the project ahead of time, the boss demanded that John __ extra hours.

   A. work           B. worked             C. works         D. should be working