We spend about one-third of our lives sleeping. We know relatively little about sleep.

A. He should not have been envious of his brother's achievement.

B. He cannot have known that his brother graduated with very high marks.

C. That his brother graduated with flying colors must have been appreciated by him.

D. He may not know that his brother is flying gradually up in a colorful balloon.

A. The car was very expensive so that he couldn’t buy it.

B. The car was too expensive for him to buy.

C. He was rich enough to buy the car.

D. He was so poor but he bought the car.

A. Peter dream of getting promotion.

B. Peter told his friend if his friend getting a promotion.

C. Peter asked his friend on getting a promotion.

D. Peter congratulated his friend on getting a promotion.

A. We were expected to be offered him the job.

B. He expected to be offered the job.

C. He is expected that we should offer him the job.

D. He was offered the job without expectation.

A. Not only overeating but also physical inactivity may lead to several deadly diseases.

B. Apart from physical activities, eating too much also contributes to several deadly diseases.

C. Both overeating and physical inactivity result from several deadly diseases.

D. Overeating and physical inactivity are caused by several deadly diseases.

A. He would retake the exam if he didn’t miss too many lessons.

B. He could have retaken the exam if he hadn’t missed too many lessons.

C. If he missed too many lessons, he wouldn’t retake the exam.

D. If he had missed too many lessons, he wouldn’t have retaken the exam.

A. He has official permission to practise primitive religion.

B. He is famous for his vast knowledge of primitive religion.

C. He has authority over the people who practise primitive religion.

D. He has a great influence on the people who practise primitive religion.