1．热力学第一定律：如果外界既向物体传热又对物体做功，那么物体内能的增加量就等于______________________________________________________________________.

4．改变内能的两种方式：_____________和________________.

二、能量守恒定律   

3.物体的内能：  物体内_____________________________________,也叫___________.

物体的内能与物体的______________、_______________有关．

因分子在永不停息地做无规则的热运动，所以任何物体__________________________.

2．分子的势能：

  分子势能的变化与            做功密切相关．

  r>ro时，分子间作用力表现为        ，当增大r时，分子力做     功，分子势能            

  r<ro时，分子间作用力表现为______，当减小r时，分子力做_____功，分子势能______.

  当r=ro时，分子势能具有________值．

    从宏观上看，分子势能与物体的_____________有关．

    对于气体，分子间的作用力_____________，分子势能和体积___________.

1．分子的平均动能：                                                        的平均值．

             是分子热运动的平均动能的标志。

  问题：比较O℃的铁和O℃的铜分子的平均动能的关系．

        比较O℃的铅球静止和运动时分子的平均动能的关系．

经典题型：1．C  2．D  3．A 4．D  5．B  6．D  7．AB

      is my room .My room      white . I have a bed .My soccer ball is       the bed. I have a table .My books are     the table. I have an             .I don’t have a TV.

     My name is Frank. I am from America. Here is a picture of my class. We are in Class one, Grade 7.My school is a junior high school. We learn Chinese in our school. Our Chinese teacher’s name is Jenny hall. Can you see her in the picture?

You can see my friends in the picture, too, Jimmy is tall. He likes to play basketball. He likes to eat fried chips. May is short and she wears(穿着)a yellow dress. She likes math. Her favorite food is hamburgers. Sandra has long hair. She can speak French. She likes ping-pong. Sally is a black girl. She has short hair. She likes to swim .She likes to eat ice cream. She eats it after lunch .I like music .Can you find me? I like to eat fruit. Maria likes computer very much .She plays computer games very well .Nick is big. He is fun. He can play soccer .He likes carrots best.

 Send me a picture of your class and tell me about your friends!

Yours,

Frank.

根据短文内容，填写下表：

Names

What he/she likes

What he/she likes to eat

Frank

May

Nick

Jimmy

Sally

八，用方框里的单词填空。（10分）

(     )9、A、Not     B、Doesn’t  C、No       D、Don’t