题目

One morning I wasted nearly an hour watching a tiny ant carry a hug feather．Several times, it   1    several obstacles in its path．And after a momentary pause it would make the necessary detour （绕道）．  2   one point, the ant had to cross a crack about 10mm wide．After some   3   thoughts, the ant laid the feather over the crack, walked   4   it and picked the feather up on the other side, then continued on its way．I was  5   by the cleverness of this ant．It was only a small insect, lacking in   6   yet equipped with a brain to reason, explore, discover 一个长方形的长和宽扩大到原来的2倍，面积就扩大到原来的4倍．