请帮忙解释一下下面第11题不选if的原因

Long long ago there lived many mice in an old house. They were free to do 1 . They ate up a lot of food. So 2 owner of the house wanted to stop the mice 3 food. He got a cat. 4 , some of the mice were killed. One day one of the oldest mice said, "All the mice 5 come to my hole tonight, and we'll decide 6 next about the cat. "
Each of the mice arrived. They thought 7 and did what they could to find a way to save their 8 . They spoke, sitting face to face, but none of them had an idea. Finally a young mouse stood up and said, "Why 9 tie a bell 10 the cat's neck? Then, 11 the cat comes close, we will hear the bell and 12 . Then the cat won't 13 catch any more of us. "
"It 14 good! Who can do so here?" the oldest mouse asked. At this very moment the hole was quiet and no one answered.
At last he said, "It's 15 to say than to do. "
1. A. nothing B. someth

请帮忙解释一下下面这段话的意思 请帮忙解释一下下面消息的大致意思 请帮忙解释一下下面的语句（matlab） 请帮忙解释一下下面这段有关股票的话，多谢! 请帮忙解释一下下面asp代码个部分的作用！ 请哪位J2EE高手帮忙解释一下下面这断代码 请大家帮忙解释一下下面这个句子的一些难点 帮忙解释一下下面两个介词 请大家解释一下下面这首诗? 请帮忙解释一下。