袋子中装有4个黑球2个白球，这些球的形状、大小、质地等完全相同．在看不到球的条件下，随机地从这个袋子中摸出一个球，这个球为白球的概率是____．

   I have a good friend at home. Her name is Mimi. She is white and yellow. She is very cute. I play with her when(当……的时候) I have time. She likes fish very much. When she is behind (在……之后) the sofa or in her box, you can’t see her. When I sit on the sofa, she sits with me. In the evening I do my homework at my desk, and she is on the desk. At that time I put her down(放下). Then she sits next to me. Is she a good friend of mine?

①阳光   ②杂草   ③水分   ④土壤   ⑤田鼠    ⑥空气   ⑦蝗虫  ⑧稻