题目

下列现象：（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（ ） A . （1）（2） B . （1）（3） C . （2）（4） D . （3）（4）The Siberian tiger is one of the most beautiful animal in the world.It is also one of rarest.Today only about 1,000 are left, some of them are in the Hunchun Nature Reserve.The Chinese government has created the reserve to help saving the tiger’s natural habitat.But the Siberian tiger is the only endangered species.Other famous animal in a danger is the giant panda, whose habitat is in China.The panda was the symbol of the World Wide Fund for Nature.Thanks of scientists’ hard work, the number of the pandas lived in the wild has increased to about 1590.