A. B. C.
D. E. F.
As a famous dancer, she needs ____ (dance) for two hours every day.
三国两晋南北朝时期，出现了哪些杰出的科学家？他们各有什么贡献？
下面实数比较大小正确的是（ ）
What size do you want? ____
B. 
C. 
E. 
F. 
