( )合称计算机的主机。
A．CPU和输入输出设备B．CPU和外部存储器C．CPU和内部存储器D．运算器和控制器
参考答案：C
补全对话。
A: __1__ your favourite food?
B: My favourite food is candy.
A: __2__ it __3__ food?
B: __4__ , it isn't. It is __5__ food.
A: What's your favourite __6__ ?
B: My favourite drink is juice.
A: That's good. It is a __7__ drink.
B: Yes. It is good for our health.
A: __8__ you __9__ __10__ juice here?
B: Sorry, I haven't got any juice here.
某班一个小组七名同学在为地震灾区“爱心捐助”活动中，捐款数额分别为：10，30，40，50，15，20，50（单位：元）．这组数据的中位数是______（元）．
