构成膜攻击复合物(MAC)的补体成分是()
A.C6b~C9
B.C4b2a
C.C3bnBb
D.C3bBb
E.C5b~C9
参考答案:E
With the popularity of ______ cell phone, more and more people are addicted to it and do less and less face-to-face communication, which has become _______ widespread concern.
A.the; a
B.\; \
C.the; \
D.a; the
某商品流通企业为了扩大销售额,选定了四种方案,四种方案所需费用与可能得的销售额的预计数如下表所示:
用价值分析方法选择比较满意的方案是()。
A.方案一
B.方案二
C.方案三
D.方案四