我省小学生聂利为了探究“蜜蜂靠什么发声？” 她剪去蜜蜂的双翅，蜜蜂依旧发出“嗡嗡”的声音，结果表明：蜜蜂并不是靠{#blank#}1{#/blank#} 发声的。她又用大头针捅破了蜜蜂翅膀下的小黑点，蜜蜂就不发声了。聂利认为蜜蜂的发声器官就是小黑点。不管聂利的发现是否正确，我们应该学习她的{#blank#}2{#/blank#} 。

Do you know Marc Yu (余俊承). He is very famous . He is only nine years old. He is a Chinese American. His mother is from Macao. He likes music very much and he has great musical talent（天赋）. He can play forty pieces of classical music now.
After hearing Mary Had a little Lamb one time at the age of three, he began playing it on the piano. Before that, he didn’t learn the piano at all. He started to take the piano lessons at the age of three. His first public performance（表演） was at the age of three , too.
Now he can play great music for people on the stage. He wants to be a famous musician like Lang Lang in the future. He likes LangLang very much. Lang Lang is his idol.

In England, afternoon tea, taken between four and five, is the most informal(非正式的) meal of the day. If you are a friend of the family, you may drop in for tea without an invitation（邀请） or telling that you are coming. Very often it is not served at a table. The members of the family and visitors take tea in the sitting room. Each person has a cup and saucer(托盘)，a spoon and a small plate for bread-and-butter and cake. By the way, do not help yourself to cake first; bread-and-butter first, then cake if there is any. Another piece of advice: Do not put more than one piece of bread or cake on your plate at the same time.

In England, afternoon tea, taken between four and five, is the most informal(非正式的) meal of the day. If you are a friend of the family, you may drop in for tea without an invitation（邀请） or telling that you are coming. Very often it is not served at a table. The members of the family and visitors take tea in the sitting room. Each person has a cup and saucer(托盘)，a spoon and a small plate for bread-and-butter and cake. By the way, do not help yourself to cake first; bread-and-butter first, then cake if there is any. Another piece of advice: Do not put more than one piece of bread or cake on your plate at the same time.

化简：（2a+1）（2a﹣1）﹣4a（a﹣1）

化简：（2a+1）（2a﹣1）﹣4a（a﹣1）