山东烟台一母亲来信说:我的儿子今年上二年级,是个聪明活泼的小男孩,家人都非常喜爱他。可是自从上小学以来,忧虑就一直伴随着我们家长。儿子的活泼好动不像以前那样可爱了,他上课时自己走神不说还调皮捣蛋,做作业时不专心,记性也不好,交待过好几遍的事情还老是忘记。怎么办呢? A letter from a mother in Yantai, Shandong Province, said: My son is a sophomore and a young boy. His family loved them very much. But since I was in elementary school, my anxiety has been with our parents. His lively and amiable son is not as cute as before. When he was in class, he did not say anything but naughty, did not concentrate on his homework, and did not remember well. He has always forgotten things he has done several times. How to do it?