My name is Dave. I have three good friends, Jack, Tom and Jim. Jack likes cakes, Tom likes fruit, Jim likes eggs and I like vegetables. We all like hamburgers. We eat hamburgers for lunch every day. Jack and Tom like French fries , and I also(也) like French fries, but Jim doesn't like them. For dinner, I don't like chicken,    ⑶    Jack, Tom and Jim like it. They all think chicken is very delicious.

根据短文内容，回答下列问题。

在一个不透明的袋子里装有黄色、白色乒乓球共40个,除颜色外其他完全相同．从这个袋子中随机摸出一球,放回．通过多次摸球实验后发现,摸到黄色球的概率稳定在15%附近,则袋中黄色球可能有____ 个．

对有性生殖的生物来说，减数分裂与受精作用最重要的意义是____．