TCP/IP协议主要在下列哪种网络中使用()
A、局域网
B、企业网
C、广域网
D、以上说法都不正确
参考答案:C
If Newton lived today, he would be surprise by what () in science and technology.
A. had discovered
B. had been discovered
C. has discovered
D. has been discovered
100克含碳酸钙(CaCO3)90%的石灰石中,所含钙元素的质量是( )
A.90克
B.36克
C.18克
D.12.5克