Many leaders of the world got together in Copenhagen in order to find ways for people all over the world to ______ the nature

Only when I left home to go to college ___ how much my mother had done for me.

Linda, why not drive Zhongshan Road?— It’s blocked because a subway ______ there

Guess what! I haven’t used this pen for ages and it ______.

Responsibility is one of the top qualitiesparents want their children to have when they _______