一天,爸爸拿了一截木头,问我:“你看看,出这段木头的那棵树有几岁?”我知道看树的年龄应该数年轮,于是数了数,一共是11圈。我想:外面那层是树皮,不能算;第二层好像也不能算。11个圈去掉两个,于是我十分肯定地说:“9岁!”爸爸却笑着说:“不对!”我又说:“那就是11岁!”可爸爸还是说不对,并让我查查资料。可是我翻了好几本书,也没能得出结论。前两天,我看见了在中学教生物的胡老师,想起年轮的事,便向他 One day, my father took a piece of wood and asked me: “How old is the tree out of this piece of wood?” I know that the age of the tree should be years, so the number is a total of 11 . I think: the outer layer is the bark, can not count; the second layer does not seem to count. 11 rings removed two, so I am very sure to say: “9 years old!” Dad laughed and said: “no!” I said: “that is 11 years old!” But my father still said no, and let me check research. But I turned over several books, did not conclude. Two days ago, I saw Mr. Hu, who taught biology in high school, and remembered the growth ring and told him