A number of these detentions can be overcome by ship crews being observant and ______ when conducting their routine testing.
A.seaworthy
B.vigilant
C.authoritative
D.conversant
正确答案是B
A number of these detentions can be overcome by ship crews being observant and ______ when conducting their routine testing.
A.seaworthy
B.vigilant
C.authoritative
D.conversant
正确答案是B