异位妊娠发生于输卵管妊娠的百分率是
A.30%
B.50%
C.70%
D.80%
E.95%
参考答案:E
___ the website of the Fire Department in your city, and you will learn a lot about firefighting.
A.Having searched
B.To search
C.Searching
D.Search
以下哪个行业不属于周期性行业?
A.钢铁
B.煤炭
C.有色金属
D.商业连锁