《船舶载运危险货物应急措施表》中对火灾的应急行动分()种情况给予不同的应急措施。
A.2
B.3
C.4
D.5
参考答案:A
He did not regret saying what he did but felt that he ______ it differently. [ ]
A. could express
B. would express
C. could have expressed
D. must have expressed
简述知识产权制度的作用。