Man has never ceased to search for cures for such ________ diseases as cancer and AIDS.

________ I remember, his writings always had the same meticulous descriptive quality.

I really don＇t know how to ______ the problem.

Investigations ______ the origin of life on the earth have shown that, given earth-like conditions, the formation of life is almost inevitable.

In the miserable days, his kind words gave me great ______.

In some families there is a _______ battle between the young and the old.

In Shenzhou VI, Chinese astronauts aren＇t only spaceship drivers, _______ machine repairers and scientists.

In recent years much more emphasis has been put ________ developing the students＇ productive skills.

In chemical factories, employees sometimes receive _______ pay for doing dangerous work.

In Britain, the best season of the year is probably ____spring.

I＇m sorry to have taken up too much of your _______ time.