题目

Sam is a little boy, and he is only seven years old. One day he goes to the cinema(电影院). It is the first time for him to do that. He buys a ticket and then goes in. But after two or three minutes he comes out, and buys a second ticket and goes in again. After a few minutes he comes out again and buys the third ticket. Two or three minutes later he comes out and asks for another ticket. Then the girl in the ticket office asks him, “Why do you buy so many tickets? How many friends do you meet?” Sam answers, “No, I have no friends here, but a big boy always stops me at the doo下图为两种不同类型的生物细胞模式，请分析回答：（1）填写下列序号结构名称A B C 1 3 5 （2）若将细胞乙放在光学显微镜下观察，一般不容易看到的结构是 。（3）一般地，植物具有而动物不具有的能量转换器是图中的 。（4）吃西瓜时，我们会感到甘甜可口，主要是因为 内含有溶解着糖分的 。