通常采用MB(兆字节)作为PC机主存容量的计量单位，这里1MB等于( )字节。
A．210
B．220
C．230
D．240
参考答案：B
What do you _____________ for lunch?[ ]
A. have
B. has
C. had
售货员的操作技术，“准”必须做到哪三个坚持？
