问题 单项选择题 B1型题

力点位于阻力点和支点之间的杠杆模式()

A.平衡杠杆

B.省力杠杆

C.无力杠杆

D.速度杠杆

E.减速杠杆

答案

参考答案:D

解析:支点在力点与阻力点中间,主要作用是传递动力和保持平衡,故称之为“平衡杠杆”。阻力点位于力点和支点之间,力臂始终大于阻力臂,可用较小的力来克服较大的阻力,有利于做功故称之为“省力杠杆”。力点位于阻力点和支点之间,力臂始终小于阻力臂,力必须大于阻力才能引起运动,不省力,但可以获得较大的运动速度,故称之为“速度杠杆”。

阅读理解

任务型阅读。

     Can plants eat people? Probably not, but there are many plants that eatmeat. Some of them are big,

and they can eat small animals. One famous meat-eating plant is the Venus flytrap.

     The Venus flytrap is a very strange plant. It grows in dry parts of the United States. Its leaves are like

the pages of a book. 3. They can open and close very quickly. Inside the leaves. there are three small

hairs. If an insect touches one of the hairs, the leaf closes quickly. The insect cannot get out. In about half

an hour,the leaf presses the insect until it is dead. Then, the plant covers. the insect with a special liquid

(液体). Slowly, the plant eats the insect.

     Plants arc living things that have leaves and roots and grow in earth.

     4. Most of them get energy from the sun, the air, and the ground. In some places,the ground is very

poor. It doesn't have all the important things that plants need, especially nitrogen (氦). Animal meat has a

lot of nitrogen, so some plants eat meat to get what they need. Let's hope that some of the bigger plants

don't get the same idea!

1. Why is Venus flytrap a famous plant?

    ____________________________________.

2. In some places, why do some plants get energy from animal meat?

   _______________________________________________________.

任务(二)

把文中划线部分译成汉语。

3. ______________________________________________________。

4. ______________________________________________________。

任务(三)

请给短文选一个适当的英文标题。

5. Which is the best title of this passage?

A. Meat-eating plants

B. Can plants eat people?

C. The Venus flytrap is a very strange plant

D. Animal meat has a lot of nitrogen

问答题 简答题