第1题：
_____ of the controllable pitch propeller enables the blades to be moved to change the pitch angle
A.An external mechanism
B.An internal mechanism
C.An interlock device
D.A hunting gear system
第2题：
第3题：
Propeller pitch speed minus ship speed divided by the propeller pitch speed is termed ___.
A.apparent slip
B.true slip
C.pitch
D.propulsive efficiency
第4题：
The most powerful signal of stress is a change of pitch on the vowel.（）
第5题：
Pitch is produced by frequency of vibration of the vocal cords. The higher the frequency, the higher the pitch.（）
A对
B错
第6题：
第7题：
“他说话声音高，真可以说是声如洪钟”的“声音高”是指音高。
A对
B错
第8题：
Compared to a constant pitch propeller, a controllable pitch propeller
A.more efficiently uses available engine power
B.operates at a lower efficiency at a fixed speed
C.produces the same torque at lower engine power
D.develops its rated power at a lower speed
第9题：
音名（Pitch name）
第10题：
pitch（）