第17题: [单项选择]One of the principal dangers inherent in liquefied petroleum gas is(). A. as it warms up it becomes heavier than air B. the way it reacts with sea water C. the strong odor it produces D. its low temperature causes frostbite or freezing 参考答案:D
第25题: [单项选择]如果使用26位掩码来划分子网,下面哪个地址是有效的子网()。 A. 172.16.43.16 B. 172.16.128.32 C. 127.16.243.64 D. 172.16.157.96 E. 172.16.47.224 F. 172.16.192.252 参考答案:C