题干
1 How long is it ? ____ A It's in the east of America.
2 How big is Beijing ?____ B Beijing's got about fourteen million people.
3 Are you a teacher ? ____ C It's in the northeast of China.
4 Where's Harbin? ____ D Yes, I am .
5 Where's New York ?____ E It's about two thousand kilometres.
答案(点此获取答案解析）
E,B,D,C,A
s，那么它从斜面中点到顶端所用时间为（ ）
，则b与