A.EBLB.VRMC.CRTD.Grease pencil（）is not used in modern r……

单项选择题（）is not a job of the radar antenna.

A.To receive the high-frequency pulses from the transmitter
B.To focus the pulses into a beam，and send them into space
C.To pick up reflected pulses coming from objects that have been struck by the beam
D.To reflect microwaves

单项选择题You are using a radar in which your own ship is shown at the center，and the heading flash always points to 0°. If bearings are measured in relation to the flash，what type of bearings are produced? （）

A.Relative
B.TRUE
C.Compass
D.Magnetic

单项选择题You are underway in thick fog. You have not determined if risk of collision exists. Which statement is TRUE?（）.

A.Your speed must be reduced to bare steerageway
B.A look-out is not required if the radar is on
C.Fog signals are only required when a vessel is detected by radar
D.The radar should always be kept on a short-range scale

单项选择题You are underway in restricted visibility and hear a fog signal forward of the beam. Nothing appears on your radar screen. You must（）.

A.stop your engines
B.sound two prolonged blasts of the whistle
C.sound the danger signal
D.slow to bare steerageway

单项选择题You are underway at 5 knots and see on your radar a contact 10 miles directly astern of you. 12 minutes later，the contact is 8 miles directly astern of you. What is the estimated speed of the contact? （）

A.Dead in the water
B.1 knot
C.10 knots
D.15 knots