单项选择题
A.3 short blasts of the ship's whistle B.1 short blast of the ship's whistle C.3 long blasts of the ship's whistle D.1 long blast of the ship's whistle
A.bridge B.forward station C.aft station D.any hold in which the stevedores are working
A.removing the top half of the shell，cutting the line at its source，and renewing completely B.cutting the line where it enters the case and replacing that portion C.leaving the original line and tying another one to it so the two lines will take the strain D.an approved servicing facility ashore