东汉乐府民歌的特点是()
A.重复歌唱的章法,和谐的韵律
B.叙事性成分增多,有些描写人物形象
C.抒情真挚、浓郁
D.以四字句为主,兼有五六言
参考答案:B, C
—The radio is too noisy and there is nothing interesting on it. Why don't you ?
—All right. I'll do that.[ ]
A. turn it on
B. turn it off
C. turn it back
D. turn it up
PLC设计规范中,RS232通讯的最大距离是()。
A.1200m
B.500m
C.30m
D.15m