问题
选择题
The main cause of the disease in China is drug abuse, ________is very serious in Yunnan.[ ]
A.what
B.who
C.that
D.which
答案
答案:D
The main cause of the disease in China is drug abuse, ________is very serious in Yunnan.[ ]
A.what
B.who
C.that
D.which
答案:D