问题
选择题
It is uncertain side effect the medicine will bring about , though about one thousand patients have taken it.
A．that
B．whether
C．what
D．how
答案
答案：C
题目分析：句意：尽管大约1000名病人使用了这种药，但它会带来什么样的副作用还不清楚。此处what修饰名词side effect。故选C。