如图是贮水式贴身暖(电热水袋),其面料为:高强度PVC(聚氯乙烯)、短绒印花布复

题型:选择题

问题:

如图是贮水式贴身暖(电热水袋),其面料为:高强度PVC(聚氯乙烯)、短绒印花布复合面料;额定电压为220V、额定功率为600W;温度范围为68-75℃,根据以上信息,试判断下列有关贮水式贴身暖的说法不正确的是(  )

A.贴身暖加热水温升高时,具有的内能逐渐增大

B.贴身暖可将手捂热是利用了热传递的方法

C.高强度PVC属于无机非金属材料

D.若贴身暖接入110V电路中,它的额定功率仍为600W

考点:物体内能的改变方法(做功、热传递)
题型:选择题

多样性指数的大小与种的数目有关而与种的均匀度无关。( )

题型:选择题

甲、乙两车分别以均匀的速度在周长为600米的圆形轨道上运动。甲车的速度较快,当两车反向运动时,每15秒钟相遇一次,当两车同向运动时,每1分钟相遇一次,求两车的速度。

题型:选择题

Life in 2060

  Let us suppose it is now about A.D. 2060. Let’s make believe (假装;虚构) it is about sixty years from now. Of course, things have changed and life is very different.

  Voyages to the moon are being made every day. It is as easy to take a holiday on the moon today as it was for the people in 1960 to take a holiday in Europe. At a number of scenic spots on the moon, many hotels have been built. The hotels are air-conditioned, naturally. In order that everyone can enjoy the beautiful scenery on the moon, every room has at least one picture window. Everything imaginable is provided for entertainment (娱乐) of young and old.

  What are people eating now? People are still eating food. They haven’t yet started to take on heir (继承) supply of energy directly as electrical current or as nuclear power. They may some day. But many foods now come in pill form, and the food that goes into the pill continues to come mainly from green plants.

  Since there are several times as many people in the world today as there were a hundred years ago, most of our planet’s surface has to be filled. The deserts are irrigated with water and crops are no longer destroyed by pests. The harvest is always good.

  Farming, of course, is very highly developed. Very few people have to work on the farm. It is possible to run the farm by just pushing a few buttons now and then.

  People are now largely vegetarians (素食者). You see, as the number of people increases, the number of animal decreases. Therefore, the people have to be vegetarians and we are healthier both in our bodies and in our minds, and we know the causes and cure of disease and pain, and it is possible to get rid of diseases. No one has to be ill any more.

  Such would be our life in 2060.

  

1. When was the passage written?

  A. In about A.D. 2060.

  B. In about 1960.

  C. In about 2000.

  D. In about 2004.

2. According to the passage, what will be on the moon in about A.D. 2060?

  A. Many tourists.

  B. Many other animals.

  C. Many plants.

  D. A sea.

3. What will people eat then according to the passage?

  A. Biscuits in pill form.

  B. Foods in pill form.

  C. Foods in water form.

  D. Foods in gas form.

4. The passage tells us that in 2060, ____ on the earth than now.

  A. there are fewer population

  B. there are more pests

  C. there is less water

  D. the crops are getting better

5. Why are people largely vegetarians in 2060?

  A. Because they don’t eat meat.

  B. Because doctors advise them not to eat meat.

  C. Because the number of animals decreases.

  D. Because all the animals have died of diseases.

题型:选择题

对流传热膜系数的单位是()。

A、W/(m2•℃)

B、J/(m2•℃)

C、W/(m•℃)

D、J/(S•m•℃)

题型:选择题

下列windowsxp账户管理注意事项中说法错误的是:()

A.任何类型的用户都可以进行添加和删除账户的操作

B.只有管理员用户才可以进行添加.删除账户的操作

C.不能删除当前正在使用的账户

D.系统至少应该有一个管理员用户

更多题库