问题 问答题

为研究影响家用保温瓶保温效果的因素,某同学在保温瓶中灌入热水,现测量初始水温,经过一段时间后再测量末态水温.改变实验条件,先后共做了6次实验,实验数据记录如下表:

序号瓶内水量/mL初始水温/℃时间/h末态水温/℃
1100091478
2100098874
3150091480
41500981075
5200091482
62000981277
下列研究方案中符合控制变量方法的是______.

(A)若研究瓶内水量与保温效果的关系,可用第1、3、5次实验数据

(B)若研究瓶内水量与保温效果的关系,可用第2、4、6次实验数据

(C)若研究初始水温与保温效果的关系,可用第1、2、3次实验数据

(D)若研究保温时间与保温效果的关系,可用第4、5、6次实验数据.

答案

由题意知,影响保温效果的因素有瓶内水量、初始水温及时间,则要探究水量与保温效果的关系,应选控制初始温度及时间相同,而改变水量,故可以选1、3、5三组数据;

故A正确,B错误;

而要研究初始水温与保温效果的关系,应控制瓶内水量、时间不变,改变初始水温,故由表中数据无法探究;

要研究保温时间与保温效果的关系,应控制水量、初始水温不变,改变保温时间,而4、5、6三组中初始水温及时水量均不同,故无法探究;

故选A.

解答题
阅读理解

阅读下列短文,从每题所给的A、B、C和D项中,选出最佳选项,并在答题卡上将该项涂黑。

Michael, a typical American, stays home on workdays. He plugs into his personal computer terminal in order to connect with the office. After work, he puts on his headphones, watches a movie on his home video recorder, or plays baseball on the computer. On many days, Michael doesn’t talk to any other human beings, and he doesn’t see any people except the ones on television. Michael is imaginary, but his life style is very possible. The inventions of modern technology seem to be cutting us off from contact with our fellow human beings.

The world of business is one area in which technology is isolating us. Experts say, for example, that many people will soon be able to work at home. With access to a large central computer, employees such as office clerks, insurance agents, and accountants could do their jobs at display terminals in their own homes. They would never have to actually see the people they’re dealing with. In addition, the way employees are paid will change. Workers’ salaries will be automatically paid into their

bank accounts, making paper checks unnecessary. No workers will stand in line to receive their pay or cash their check. Personal banking will change, too. Customers will deal with machines to put in or take out money from their accounts. Another area that technology is changing is entertainment. Music, for instance, was once a group experience. People listened to music at concert halls or in small social gatherings. For many people now, however, music is an individual experience. Walking along the street or sitting in their living rooms, they wear headphones to build a wall of music around them. Movie entertainment is changing, too. Movies used to be social events. Now fewer people are going out to see a movie. Many more are choosing to wait for a film to appear on television or are borrowing videotapes to watch at home. Instead of laughing with others, viewers watch movies in their own living rooms.

小题1:After work, Michael likes to ________.

A.listen to music at the concert hall

B.watch a movie in his living room

C.run a program on his computer in his office

D.play baseball with his workmates小题2:Which of the following is NOT mentioned in the passage?

A.Clerks will be able to work at home.

B.One can play baseball on the computer.

C.One can listen to music without disturbing others.

D.One can borrow books from libraries at home.小题3:The sentence “Michael is imaginary, but his lifestyle is very possible” means ________.

A.Michael is a person full of imagination and he can make his dreams come true

B.Michael is not a real person but the lifestyle does exist

C.Michael has ambitions but he can’t make his dreams come true

D.Michael is a person full of imagination and his lifestyle is common nowadays小题4:What will the author most probably discuss after the last paragraph?

A.Games and sports.

B.Personal banking.

C.Music and films.

D.International business.