I can ________ remember that there was a time when a deep blue sky, the song of the birds, moonlight and flowers could never have kept me spellbound.

We should ________ adjust ourselves to the development of our society.

Trees need water to grow; _____, friendship needs our heart and passion to develop.

It is useless to argue with him. You might just____  go to the seaside to argue with the sea.

The island is ____ attractive in spring and autumn because of the pleasant weather in both seasons.

As is often pointed out, knowledge is a two-edged weapon which can be used ________ for good or evil．

Recent studies have discovered that fathers uniquely contribute to the development of their children, _____ in low income families.

Traffic is bad, ______ in the city center during the rush hours.

Although the country has had political independence for over a century,   it needs the support of its neighbors.

Nowadays the roles of husband and wife are not as   defined as before, especially when both partners work and earn money for the family.