海拔高度（单位：米）
0
100
200
300
400
…
平均气温（单位：℃）
22
21.5
21
20.5
20
-- Because there is too much t____ （交通） in the street.
判断下面话的对错．
因为 39 = 13 ，所以 39 的分数单位是 13 ．
圆柱底面直径为2cm，高为4cm，则圆柱的侧面积为（ ）cm2
The famous piano teacher ______ Robby as a student only because he said it had always been his mother's dream to hear him play the piano.
