Little _____ about her own safety, though she was in great danger herself.

A．did Mary care

B．Mary did care

C．Mary does care

D．does Mary care

在下列有关声卡的叙述中，错误的是

A．采样和量化电路主要用于把模拟信号转换为数字信号

B．声卡中只有模-数转换器而没有数-模转换器

C．数字信号处理器(DSP)用于数字声音的编码、解码等操作

D．声卡具有将波形声音和MIDI音乐等进行混音和音效处理的功能