根据城市用地的性质、功能，结合自然地形，规划地面形式可分为平坡式、台阶式和混合式，用地自然坡度小于5%时，宜规划为( )。

A．混合式
B．台阶式
C．斜坡式
D．平坡式

听句子，缩写原文。（）

A．Effective self-management skills are key to academic and career success.

B．If you spend a lot of time on your school work, you will become a good manager later.

C．School work can be time-consuming and is likely to make you feel exhausted after class.

D．Good management calls for more time and energy on the part of the academic staff.