When will the float-free emergency position indicating radiobeacon be activated after abandoning ship? （）

单项选择题When using the radar for navigating（）.

A.the best fix is obtained by using a tangent bearing and a range
B.and using two radar ranges for a fix，the objects of the ranges should be close to reciprocal bearings
C.and using ranges，the most rapidly changing range should be measured last
D.and crossing a radar range of one object with the visual bearing of a second object，the two objects should be 80°to 110°apart

单项选择题When using the ARPA in heavy rain，which action should you take? （）

A.Increase the radar gain to pick up weak echoes through the rain
B.Increase the STC setting to reduce close-in spurious signals
C.Navigate as though the effective range of the radar has been reduced
D.Increase the range of the inner and outer guard rings

单项选择题When using an ARPA，what should you consider in order to evaluate the information displayed?（）

A.The target vessel's generated course and speed are based solely on radar inputs
B.Navigational constraints may require a target vessel to change course
C.The trial maneuver feature will automatically determine a course that will clear all targets
D.You cannot determine if a small target has been lost due to sea return

单项选择题When using a radar in a unstabilized mode，fixes are determined most easily from（）.

A.center bearings
B.tangent bearings
C.ranges
D.objects that are close aboard

单项选择题When navigating in thick fog with the radar on，you should（）.

A.station the look-out in the wheelhouse to keep a continuous watch on the radar
B.secure the sounding of fog signals until a vessel closes within five miles
C.station a look-out as low down and far forward as possible
D.keep the radar on the shortest available range for early detection of approaching vessels