膜脂的双分子层结构及其适当的流动性是膜蛋白保持一定构象表现正常功能的必要条件。

题型:判断题

问题:

膜脂的双分子层结构及其适当的流动性是膜蛋白保持一定构象表现正常功能的必要条件。

考点:化学工程生物膜生物膜题库
题型:判断题

C60的分子结构形似足球(如下图所示)。关于C60的说法中,错误的是( )

A.它是一种单质

B.每个C60 分子由60个碳原子构成

C.它与金刚石是同一种物质

D.它完全燃烧后的产物是CO2

题型:判断题

Chinese press, thousands of tourists and space experts from Japan, Germany, Italy and other countries have gathered at China’s Xichang Satellite Launch Center in southwestern Sichuan Province on Tuesday, October 23 to witness the historic moment-the launch of the nation’s first moon orbiter (人造卫星), which is scheduled to take place at 6:05 p.m.on Wednesday.

Space center experts were worried earlier in the day when Xichang experienced an unexpected rainfall from about 4:05 a.m.till 7:10 a.m.on Wednesday, but they were able to breathe a sigh of relief when the weather cleared.Both national and local meteorological observatories (气象台)forecast cloudy weather for the launch site on Wednesday afternoon.However they said they believed it would not affect the launch mission, an opinion which was shared by technological staff at the site.     

Local villagers within a radius of 2.5 km of the launch site and under the trajectory(轨道) of the carrier have been told to move to safe areas two hours prior to the planned launch.Tourists have been charged 800 yuan (105 U.S.dollars) to witness the launch of China’s first lunar satellite.A local travel agency has said that the two observation platforms are capable of holding 2,000, but it is not known how many people paid for the chance.

The moon orbiter, Chang’e-1, named after a legendary Chinese goddess who flew to the moon, and the carrier Long March 3A have passed all pre-launch tests.     

China hopes to become the 17th nation to join the International Space Station (ISS) project, and carried out its first piloted space flight in October 2003, making it only the third country in the world after the Soviet Union and the United States to have sent men into space.In October 2005, China completed its second manned space flight, with two astronauts on board.

1.Which of the following can be the best title of the passage?

A.China counting down to launch of its first lunar satellite  

B.Chang’e-1 lunar satellite and its launch

C.Chang’e-1 lunar satellite to conduct 1st orbit transfer  

D.China hopes to join the International Space Station

2.Space center experts believed _______.

A.rainfall would come as soon as possible.

B.the cloudy weather wouldn’t affect the mission.

C.All the 2,000 tourists should paid 800 yuan each to witness the launch.

D.The mission was the third time of China’s manned flight.

3.Please arrange the time order of the following events according to the passage.

a.Local villagers have been told to move to safe areas.    

b.Unexpected shower fell on the early morning of Wednesday.

c.The moon mission is scheduled to take place.        

d.Journalists and tourists gathered at the Satellite Launch Centre.

A.b c d a              B.a b c d               C.d b a c              D.c d a b

4.It can be implied from the passage that _____________.

A.China has become the 17th country to join the International Space Station         

B.China will launch its manned spaceship to the moon soon

C.China is the third nation to send men into space       

D.China is pioneering in the space exploration now

题型:判断题

操作机械刹把前,要检查刹把角度是否合适,刹车是否灵敏可靠。

题型:判断题

墩台施工用的石料分为()。

A、毛石

B、片石

C、块石

D、料石

E、圆石

题型:判断题

土层中的地下工程施工,常用的方法为()。

A.天井钻机施工法

B.地下连续墙法

C.盾构法

D.掘进机法

E.沉管法

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