①用两个钉子就可以把木条固定在墙上．

②从A地到B地架设电线，总是尽可能沿着线段AB架设．

③植树时，只要确定两棵树的位置，就能确定同一行树所在的直线．

④把弯曲的公路改直，就能缩短路程．

其中能用“两点确定一条直线”来解释的现象有（   ）

下列描述中，说明气候的是（   ）

用所给词的适当形式填空。 
（1）Do you often memorize new words by____(make) vocabulary lists?
（2）–You speak English very well. Who taught you?      -Nobody, I taught____  (me).
（3）I heard the brave policeman had caught two ____( thief ) in the street by himself.
（4）My mother often practice ____ ( dance ) at home.
（5）We want to take a trip this summer somewhere in ____(east) China.