编号
长度/cm
直径/cm
频率/Hz
1
20
1.5
2131
2
30
2.0
1284
3
50
2.5
656
A. Red is my favourite colour.
B. What time does the party begin?
C. That sounds interesting.
D. It's on 5th January.
E. Can you come to my birthday party, Linda?
Peter: ____
Linda: Sure. When's your birthday?
Linda: ____
Peter: It begins at half past six in the evening.
Linda: OK.
Peter: Please bring some red things to the party. It's a "red party". ____Linda: A “red party”？ ____ I can't wait.
对下列几种现象解释正确的是（）
下列几何图形：圆，圆柱，球，扇形，等腰三角形，长方体，正方体，直角，其中平面图形有 ____个．
