These trees____ ____ ____ ____ ____(在.中起重要作用)keeping the earth.
问题描述:
These trees____ ____ ____ ____ ____(在.中起重要作用)keeping the earth.
每空一词
____ ____ ____ ____(对......来说,......是不可能的)such a small child to work out this problem.
答
很高兴能够在这里回答你的问题,应该为:
These trees (play an important role in)keeping the earth.