题目

一批基因型为AA与Aa的豌豆，两者数量之比是1：3．自然状态下（假设结实率相同）其子代中基因型为AA、Aa、aa的数量之比为(     ) A．3：2：1 B．7：6：3 C．5：2：1 D．1：2：1 答案：BI have a friend. His name is Tim. He is 10 years old. He likes fish. His favourite colour is while. His birthday is in February. He has got a cute dog. He has big eyes, We are good friends. (1). How old is Tim?___________________________(2). Is his birthday in November?___________________________(3). What's his favourite colour?____________________________(4). What's he like?____________________________(5). Has he got a computer?______________________________