下列选项中，可以应用滤镜效果的颜色模式有（）。
A、位图
B、灰度
C、索引色
D、RGB
参考答案：B, D
引起纵隔血肿的原因为（）
A.车祸挤压伤
B.主动脉瘤破裂
C.咽后壁出血
D.自发性纵隔血肿
E.主动脉夹层破裂
— I'm sorry, I shouldn't have been so rude to you.
— You ______ your temper but that's OK. [ ]
A. have lost
B. had lost
C. did lose
D. were losing
