As you know,reading in the sun_____ your

乐队演奏乐曲时，听众能分辨出古筝和钢琴发出的声音，主要是因为它们的（　　）

A．音色不同

B．音调不同

C．响度不同

D．节奏不同

男，6天，生后4天始鼻塞流涕，烦躁不安，日渐呼吸困难，肺部呼吸音粗，少许湿性啰音，胸片肺纹理增强模糊，散在小片状阴影( )|

A.湿肺

B.胎粪吸入综合征

C.新生儿肺透明膜病

D.生后感染性肺炎

E.宫内感染性肺炎

He ___________ unwisely, but he was at least trying to do something helpful.

A．may have acted

B．must have acted

C．should have acted

D．would act

列宁称赞一位作家是“无产阶级艺术的权威”，无疑是无产阶级最杰出的代表，他对无产阶级作出了许多贡献“这位作家是谁？