陶瓦盖作用及使用范围。

Baseball is one of the favorite sports in the U.S.A. Children play baseball in sports fields or parks.

At summer picnic, there is often an informal（非正式的） baseball game. Boys and girls, young and old take turns to play. There are nine players on each team.

The baseball season goes from April to September. During this time, baseball matches are showed on TV and members of the important baseball teams become America's heroes（英雄）. At the end of the season, the two top teams play against each other. Many baseball fans go along to watch the game. Millions of others listen to the radio or watch television. People seem to talk only about the game. Even long after it is over, they still talk about the result and the players.

American football is perhaps the most popular sport in the U.S.A. The football season begins when the baseball season ends. More people are interested in football than baseball. When there is an important game, thousands of people sit beside radios or in front of television sets to get the result.

小题1: There are           players on each baseball team.

A．seven

B．eleven

C．four

D．nine小题2: The baseball season goes from          .

A．April to September

B．March to September

C．January to September

D．May to September小题3:           follows the baseball season in the U.S.A.

A. The basketball season            B. The football season

C. A basketball match           D. A football match

小题4:Which one is NOT right?

A．Boys and girls like baseball games.

B．More people are interested in football than baseball.

C．Just young boys and girls take turns to play in the informal baseball game.

D．Children sometimes play baseball in parks.小题5:           is perhaps the most popular in the U.S.A.

A. Baseball                 B. Table tennis

C. Basketball                   D. American football

1900年,如果你生活在北京城,你能亲眼目睹的侵略者的暴行是

A．八国联军屠杀义和团成员

B．英法联军火烧圆明园

C．洋枪队 * * 太平天国运动

D．列强强迫清政府签订《辛丑条约》

OTDR动态范围取决于（）、（）、（）。

管路系统的特性曲线是随着（）的增加而上升。

A、流量

B、扬程

C、轴功率

D、效率