A deadhead is a(n)（）.

单项选择题A deadhead is a(n)（）.

A.tree or log awash in a nearly vertical position
B.crew member who refuses to work
C.upstream end of a land wall
D.buoy that is adrift

1.单项选择题A barometer showing falling pressure indicates the approach of a（）.

A.high pressure system
B.low pressure system
C.high dew point
D.low dew point

2.单项选择题（）the canal transit，the radar was operating.

A.At
B.In
C.During
D.With

3.单项选择题（）should be used during the poor visibility if the radar’s screen shows heavy sea returns.

A.Gain Control
B.Brilliant Control
C.Anti-clutter Sea Control
D.Sweep Intercept

4.单项选择题（）is on the panel of radar.

A.KEYLOCK
B.REPEATER
C.STATIC INVERTER
D.ANTI-CLUTTER-SEA

5.单项选择题（）20 targets can be tracked at one time．When maximum tracking capacity is reached，no further acquisitions are possible.

A.As many as
B.So many as
C.As much as
D.As more as

6.单项选择题What will NOT induce errors into a doppler sonar log?（）

A.Increased draft
B.Pitch
C.Roll
D.Change in trim

7.单项选择题The microsecond unit of time is used in radar applications. The microsecond represents which of the following?（）.

A.one-millionth part of a second
B.one-thousandth part of a second
C.one-hundredth part of a second
D.one-tenth part of a second

8.单项选择题The minimum range at which a target can be detected is basically determined by which of the following?（）.

A.persistence
B.pulse repetition rate
C.pulse length
D.rotation rate

9.单项选择题The number of pulses of energy transmitted per second is call the（）.

A.carrier frequency
B.pulse repetition rate
C.pulse length
D.pulse repetition time

10.单项选择题The radar component that generates the radio-frequency energy in the form of short powerful pulses is which of the following?（）.

A.magnetron
B.receiver
C.indicator
D.modulator