多媒体数据压缩的基本要求是什么？
参考答案：
（1）可还原；（2）压缩比高；（3）重现精度高；（4）计算成本低；（5）实时性好。
—Did you hear that Li Hua was robbed during his recent trip to South Africa?
—Yes, not only ________ his money, but he was nearly killed.
A．he lost
B．did he lose
C．he had lost
D．was he lost
黑睛病的主要特点是，除了：
A．星膜翳障
B．畏光流泪
C．眼眵较多
D．疼痛
E．视力下降
