问题补充：
Willpower is a kind of quality, is it takes to do anything well.
A. what; which
B. what; what
C. which; which
D. which; what
答案：
A. what; which
B. what; what
C. which; which
(答案→)D. which; what
解析：考查非限制性定语从句和表语从句的引导词。第一空填which因为这是非限制性定语从句，修饰quality，在定语从句中做主语，第二空填what，是引导表语从句，表语从句中用的是It takes sth to do做…要花费…,缺少宾语：所以只能用疑问代词what补充。句意：意志力是一种品质，它也是要把事情做好所需要的（东西）。
