The operating cord on an inflatable lifera
题型：单项选择题
问题：
The operating cord on an inflatable liferaft should be renewed by（）.
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