1 . We will put off the picnic in the park until next week, ________ the weather may be better. (用适当的词填空)

2 . It is often the case ________ anything is possible for those who hang onto hopes. （用适当的词填空）

3 . Scientists have advanced many theories about why human beings cry, none of ______ has been proved. (用适当的词填空)

4 . When ________(compare) different cultures, we often pay attention only to the differences without noticing the many similarities. （所给词的适当形式填空）

5 . It’s helpful to put children in a situation ________ they can see themselves in different ways. (用适当的词填空)

6 . 我从未想到会有如此多的人在短时间内感染上这么严重的病毒。(Never; occur) (汉译英)

8 . The number of smokers, _________ is reported, has dropped by 17 percent in just one year. （用适当的词填空）

9 . The fact has worried many scientists ________ the earth is becoming warmer and warmer these years.

10 . Give me a chance, ________ I’ll give you a wonderful surprise.   (用适当的词填空)