May is _______ her diet because she knows a healthy diet is important for her.

[      ]

A. careful

B. careful of

C. careful with

D. careful for

计算机病毒是指______。

A．编制有错误的计算机程序

B．设计不完善的计算机程序

C．已被破坏的计算机程序

D．以危害系统为目的的特殊计算机程序