单项选择题
As these features are not all charted，special caution should be exercised （） vessels navigating in the vicinity.
A.by B.with C.on D.in
单项选择题 Areas enclosed by a long and short dashed magenta line indicate （）.
单项选择题 An occulting light is one in which （）.
单项选择题 AFTER DROPPING THE PILOT means （）.
