—It’snecessary

問題詳情：

—It’s necessary ____ us ____ obey the traffic rules.

       —You’re right. Everyone has but only one life.

            A. for; to                  B. for; for                   C. to; to                        D. to; for

【回答】

A    It’s+adj. (+for sb. )+to do sth. 為固定句型。故選A。

知識點：介詞和介詞短語

題型：選擇題