关于做曲线运动的物体,下列说法中正确的是() A.它所受的合外力一定不为零 B.

题型:选择题

问题:

关于做曲线运动的物体,下列说法中正确的是( )

A.它所受的合外力一定不为零

B.它所受的合外力一定是变力

C.其速度可以保持不变

D.其动能一定发生变化

考点:斜抛运动
题型:选择题

在生态系统中,从总体上看各组成成分储存的能量,排序正确的是[ ]

A、植物的数量>草食动物>肉食动物

B、草食动物>肉食动物>植物的数量

C、肉食动物>草食动物>植物的数量

D、肉食动物>植物的数量>草食动物

题型:选择题

保险人是指按照保险合同承担缴付保险费等义务的一方。( )

题型:选择题

阅读理解。

     Today just as technology changed the face of industry, farmers have undergone an "agricultural

revolution". On the farm of today, machines provide all the power.

     One of the most important benefits will be the farm computer. A few forward-looking farmers

are already using computers to help them run their farms more efficiently. The computers help them

keep more accurate records so they can make better decisions on what crops to plant, how much

livestock to buy, when to sell their products, and how much profit they can expect. Many computer

companies have been developing special computer programs just for farmers. Programs are being

written for hog(猪) producers, grain farmers, potato farmers, and dairy farmers. In the future, farmers

will be able to purchase computer programs made to their needs. Because of the growing importance

of computers on the farm, students at agricultural colleges are required to take computer classes in

addition to their normal agricultural courses. There can be no doubt that farmers will rely on computers

even more in the future. While the old-time farm depended on horse power, and modern farms

depend on machine power, farms of the future will depend on computer power.

     Another technological advance which is still in the experimental stage is the robot, a real "mechanized

hired hand" that will be able to move and, in some ways, think like a human being. Unlike farmers of

the present, farmers of the future will find that many day-to-day tasks will be done for them. Scientists

are now developing robots that will be able to shear(修剪) sheep, drive tractors, and harvest fruit.

Even complex jobs will be done by robots. For example, in order to milk their cows, farmers must

first drive them into the special barn(畜棚), then connect them to the milking machines, watch the

machines, and disconnect them when they are finished. In the future, this will all be done by robots.

In addition, when the milking is completed, the robots will automatically check to make sure that

the milk is pure. The complete mobilization of the farm is far in the future, but engineers expect that

some robots will be used before long.

1.Which sentence carries the main idea of the whole passage?  

A. The first sentence of the first paragraph.   

B. The first sentence of the second paragraph.   

C. The first sentence of the third paragraph.     

D. The last sentence of the second paragraph.  

2. According to the passage, computers can not help farmers decide _____________.  

A. how much money they can earn from their products

B. whether to plant a certain kind of crop  

C. whom to sell their livestock to  

D. when to sell their products

3. Which of the following statements is true?   

A. Farmers in the future will depend totally on computers.

B. Both computers and robots have been in use on today's farms.

C. Farmers mainly use machines on their farms at present. 

D. Farmers can do nothing without the help of computers on today

4. According to the engineers,_____________ will be done by robots in the near future. 

A. all farm work            

B. milking cows  

C. most of the farm work      

D. some house work

5. What is the best title for the passage?

A. Computer-Farmers' Best Friend    

B. Farmers in the Future   

C. Robots in the future              

D. Revolution on the farm

题型:选择题

计算机的技术性能指标主要是指

A.所配备语言、操作系统、外围设备

B.字长、运算速度、内/外存容量和CPU的主频

C.显示器的分辨率、打印机的配置

D.磁盘容量、内存容量

题型:选择题

赠与合同是指赠与人将自己的财产无偿给予受赠人,受赠人表示接受赠与的合同。 下列属于赠与合同的是( )

A.张三将上等茶叶一包送与李四,李四欣然接受;为表谢意,李四送张三茅台一瓶,张三再三推辞不掉,最终也接受了

B.王五送给赵六一筐梨,赵六家里没人,于是,王五便把梨放在赵六家的院子里,留了一张便条在赵六家门上,表明赠与之意

C.甲将其汽车交给乙,并对乙说:“这车你开吧,一直开到报废为止。”乙欣然接受

D.甲将其房屋送给长期照顾自己的乙,并要求自己在世期间,乙不得将该房出售

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