39.　　 The city isn’t what it used to be three years ago.

38.　　 It was not until yesterday that I knew he was coming.

37.　　 She asked me how long it had taken to build the bridge.

36.　　 What he has done has nothing to do with us.

35.　　 It is suggested that the experiment should be made under low temperature.

34.　　 It happened that I was free that evening.

33.　　 It is a pity that you missed the lecture made by Teacher Li.

32.　　 That we need more practice is quite clear.

31.　　 As is known to all, the compass was first made in China.

30.　　 Have you seen the girl whose composition we discussed yesterday?