Be careful when you ________ the derrick
A. operating
B. operates
C. operate
D. operated
查看答案
________ were brought back to ship from the sea
A. The crew
B. The crew member
C. A person
D. The members
Where are the derricks？ They are ________
A. in deck
B. on deck
C. at deck
D. below deck
Dry powder is used to put out ________
A. electrical fire
B. oil fire
C. common fires
D. all kinds of fires
What ________ the safe working load of the derrick？
A. is
B. be
C. are
D. has
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