先减整十数，再减一位数．
例：57－23=□
57－20=37
37－3=34
（____）A. There is a school in my village.
（____）B. There is a river on the mountain.
（____）C. There're many animals in the forest.
（____）D. There is a tree behind the building.
（____）E. There is a lake near the house.
观察下图，据图可以得出西方近代自然科学发展的主要特点是( )
2015巴黎气候变化大会通过一项气候问题的国际协议，使全球升温控制在2摄氏度以下．低碳正成为人们的共识．
