A.KEYLOCKB.REPEATERC.STATIC INVERTERD.ANTI-CLUTTER-SEA（……

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

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

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

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

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