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 Attention is called to the fact that in many cases charted depths may be decreased by up to（）.
单项选择题 Be careful（）to mix them up.
单项选择题 Can you cut down the shortlanded cargo（）half?
