影响舵效的主要因素是()。
①舵角大小;
②流经舵面的流速;
③船的转动余速;
④风流、浅水等海况;
⑤舵机性能。
A.①②③④
B.②③④⑤
C.①③④⑤
D.①②④⑤
参考答案:D
—_____?
—It's very popular in China.[ ]
A. What do you like football
B. How do you think of football
C. How do you play football
D. What do you think of football
STM-1帧的信息净负荷是指()
A.AU4信息包
B.VC4信息包
C.C4信息包
D.E1信息包