简述存储器的性能指标
参考答案：
存储容量、存储速度、数据传输率、存储器价格外存储器：硬盘存储器、光盘存储器、U盘存储器
Come and have a look ________ the ants.[ ]
A. in
B. for
C. at
I've never ______ him before.
A. heard of B. hear fromC. heard to D. hear of
