问题
There is no doubt _______ nearsightedness is a serious problem among the youth of our country.
A:/
B:which
C:whether
D:that
B:which
C:whether
D:that
正确答案是：
同类题型
From space, the earth looks blueThis is about seventy-one percent of its surface is covered by water
It’s not difficult _____ us to learn English well.
_ articles for our wall-newspaper these years, and he____ about thirty articles.
38I think Jim is the right man for the jobHe is hard-working, smart, and _______ kind-hearted