26．Even if there is no scientific proof yet ______ secondhand smoke causes cancer, there is no reason why nonsmokers should be forced to take this risk．

22．The site is fairly near the city center, ___ it can only be reached by a series of narrow streets．

23. Lucy is going to have difficulty finding a good job _______ she graduates from a key university.

29．—We’d better take some extra money ________ we need it.
—I can’t agree with you more.

22．If we know more about _______causes the problem, we may take measures before it is _______late.

18. ----Did you tell him that we’ve put off the meeting?
----No. He rushed out _____ I could say anything.

17. The film Mei Lanfang, _____ Li Ming plays the starring role, has again drawn the world’s attention to our traditional Chinese art.

9. Mr. Frank asked me a question _____ I could go with him to _____ he called the Treasure House
the next week.

15.—Will you go to the party tomorrow， Xiao Hai？
—No, ____ I was invited to.

14．It was in the village ____ he once lived ____ he got his junior education.