The camera is a souvenir(纪念品)___________ by my uncle for me when he went to Japan. I do like it.
---- You can take a walk daily if you want to keep healthy. ---- .
our earth, or else it will be no longer fit for us to live on.
Professor Williams keeps telling his students that the future to the well- educated.
Trees on the hills can stop the rains from away the soil.
What is the best way you can imagine the overuse of water in our daily life.