在ISO网络中一次可有几个模块传递数据?()
A.1
B.2
C.3
D.4
参考答案:A
—How long may I keep the book?
—You ________ keep it for two weeks.
A. may B. must C. will
依据下列矿井瓦斯相对涌出量,属于高瓦斯矿井的有()m3/t
A.10
B.12
C.14
D.16