问题
o cause people some health problems, in fact farmore serious _____ than computers do
A:knew
B:had known
C:have known
D:have been knowr
B:had known
C:have known
D:have been knowr
正确答案是：
同类题型
27 ______ he did was quite right
32．She shouldn’t be working so hard —She is 70, ___
Do you know the tower _____ in the heart of thecity — You mean the one _____ from the MingDynasty
Jack often _____ music after class.
There is no doubtone who gets to the finishing line first will win the first prize.