—Somanytouristspourintosuchbeautifulplaces.      —...

問題詳情：

      — So many tourists pour into such beautiful places.

       — I think it necessary that they _____ be well preserved.

       A. can                         B. shall                        C. should                      D. may

【回答】

C

知識點：情態動詞

題型：選擇題