3．如图在Rt△ABC中，∠C=90°∠B=30°，AB=2，

　 则AC=　　 。

2．=　　　　 　。

1．在实数 ，，　 　， ， 　中是　　　　　 无理数 。

39.Leaving→Leave　40.behind→alone　

　　　 综合提升

35.at→into　36.去掉very或者very→quite　37.are you→you are　38.but→than　

40. Leave that vase behind; you might break it.

　　　 答案：31.that→as　32.will→would　?33.Placed→Placing　34.hoped→wished　

39. Leaving it with me and I’ll see what I can do.　

38. To enjoy the scenery, Irene would rather spend long hours on the train but travel by air.　

37. As far as I am concerned, education is about learning and the more you learn, the more equipped for life are you.