铜的比热容是铅的比热容的3倍.质量相同的铜块和铅块,若它们升高的温度之比为1:2

题型:选择题

问题:

铜的比热容是铅的比热容的3倍.质量相同的铜块和铅块,若它们升高的温度之比为1:2,则它们吸热之比为(  )

A.2:3

B.3:2

C.6:1

D.1:6

考点:热量的计算
题型:选择题

关于人工流产下述哪项是错误的()。

A.人工流产是指妊娠10~21周以内用人工方法终止妊娠

B.妊娠10周以内可用吸宫术

C.妊娠10~14周可用钳刮术

D.体温二次高于37.5℃,为禁忌证

E.急性生殖器炎症为手术禁忌

题型:选择题

一个分数的分子是最大的一位数,分母是最小的合数,这个分数是______,它的分数单位是______,再减少______个这样的分数单位,它就变成了最小的质数.

题型:选择题

读美国小麦、玉米带分布图(图5-61),完成下列内容。

图5-61

(1)美国商品谷物农场主要分布在          ,其中A为         带,B为      带,这里发展商品谷物农业优越的自然条件是                                

(2)商品谷物农业属于(    )

A.粗放农业

B.密集农业

C.种植业

D.混合农业(3)商品谷物农业生产的基本特征是                                         

题型:选择题

某同学想用pH试纸测定一些物质的pH,下列做法能达到实验目的的是(  )

A.用湿润的pH试纸测定稀硫酸的pH

B.用干燥的pH试纸测定二氧化碳气体的pH

C.用干燥的pH试纸测定浓硫酸的pH

D.用干燥的pH试纸测定氢氧化钠稀溶液的pH

题型:选择题

第二节(共5小题,每小题2分,满分10分)
根据短文内容,从下框的A—F选项中选出能概括每一段主题的最佳选项。选项中有一项为多余选项。
A.Environment protection
B.Driving experience
C.Self – driving
D.Safety
E. Computing and communications
F. Wireless communications

 

 
61.

Today, the Internet is in a few cars; tomorrow, broadband (宽带) will be in all of them. Any capability a personal computer has, a car will have, including two – way wireless communications for receiving e – mail, music, and movies. When you’re crossing the lonely place, the kids can watch TV if they’re bored. Every passenger will have a video feed.

 

 
62.

    Every car will have a self – driving system linked to GPS satellites. Radar sensors (传感器) will track nearby cars. On the freeway, they’ll slow your car when the car ahead of you slows; in town, they’ll help you park without hitting other cars. At rush hour, you’ll get the routes around traffic jams and accidents. The self – driving system in a car makes it possible for the car to drive itself, though some scientists say that’s 30 to 40 years off.

 

 
63.

    Motor vehicles today represent 20 to 30 percent of the world’s energy use. In the near future, a small gasoline engine and an electric motor will be brought together. Drivers will use electricity in a storage battery for short distances. Longer term, cars might burn hydrogen or use a fuel cell that converts a fuel like hydrogen and combines it with oxygen to create power. Then the waste will be pure water.

 

 
64.

   You’ll use the voice control: “Make it a bit cooler” or “find me country music”. Lighter, more reliable electronic controls replace mechanical controls. Fiber optics (光纤) replace electrical wires and light bulbs. Seats will be air – conditioned. The car will travel with one side higher than the other when turning, just as an airplane does now.

 

 
65.

   Cars will avoid some accidents by maintaining safe following distances, and by sensing sleepy or drunk drivers. Air bags will adapt for every passenger according to their size, weight, and position in case accidents happen.
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