1 . The push-up exercises are designed to s______ your muscles. (根据首字母单词拼写)

2 . Scientists have been working hard to ________(探索) the unknown world.（根据汉语提示单词拼写）

3 . Such is human nature, that a great many people are often willing to s ____ higher pay for the privilege of becoming white-collar workers. . (根据首字母单词拼写)

4 . They do not have the courage to ________(道歉) for their actions. （根据汉语提示单词拼写）

5 . A student lost in daydreaming is hard to ______ ______(专注于)his studies. (根据汉语提示完成句子)

6 . People have been working together to record its migration and make sure that there are enough plants for it to________ ________ (以……为食) . (根据汉语提示完成句子)

7 . Doctors are aiming to________ ________(全神贯注于) prevention rather than cure.（根据汉语提示完成句子）

8 . My uncle hasn’t been able to q________ smoking, but at least he has cut down. (根据首字母单词拼写)