Ⅰ.阅读理解(共15小题；每小题2分，满分30分)
阅读下列短文，从每题所给的四个选项(A、B、C和D)中，选出最佳选项。
A
One day I saw Harold, my neighbor, putting some metal sheets around the base of his tree where he kept his bird feeder.I didn't understand why until another neighbor explained to me that Harold was trying to keep the squirrels from eating the bird food.By putting the metal sheets around the base, Harold thought the squirrels wouldn't be able to climb up the tree.
