霍奇金病首发症状为浅表淋巴结，发生于颈部者高达（）
A.45%
B.50%
C.60%
D.70%
E.90%
参考答案：D
Those students argued ________each other ________whether the research into human cloning should be carried out.[ ]
A. for; over
B. to; about
C. of; over
D. with; about
企业获准认证的有效期为( )年。
A．1 B．2 C．3 D．5
