大修理项目是指为了保证通信网络的正常运行恢复设备或线路原有性能及指标而进行的维修、维

题型:多项选择题

问题:

大修理项目是指为了保证通信网络的正常运行恢复设备或线路原有性能及指标而进行的维修、维护工作大修理项目分为哪两类()。

A.整治性大修理

B.应急性大修理

C.计划性大修理

D.以上都不是

考点:移动网络综合管理与维护成本管理、维护规程成本管理、维护规程题库
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消费者总是想用同样多的货币买到更多的商品。但从长远来看,物价持续下降、通货紧缩却不是我们所希望的,因为这会导致(   )

A.流通中的货币量减少→居民购买力下降→社会有效需求不足→生产萎缩

B.社会投资减少→生产萎缩→失业率上升→经济衰退

C.生活资料价格下降→居民购买力上升→居民消费需求增加→物价上涨

D.生产资料价格下降→企业生产成本降低→企业经济效益提高→经济过热

题型:多项选择题

具备基本的化学实验技能是进行科学探究活动的基础和保证。下列有关实验操作错误[ ]

A.倾倒液体

B.装入固体粉末

C.加热液体

D.读取液体体积

题型:多项选择题

地图是研究历史的重要工具。下图是新航路开辟过程的一条航路的示意图,对这一航路表述正确的

A.该航路证明了“地圆说”的正确性

B.葡萄牙殖民活动据点延伸至非洲

C.英国凭借此航路成为日不落帝国

D.哥伦布首开此航路发现美洲新大陆

题型:多项选择题

D/A转换器由4部分组成,它们是权电阻网络、运算放大器、基准电源和 【1】 组成。

题型:多项选择题

阅读理解。

                                                  How to wash clothes in a flash

     LAUNDRY is never an easy part of housework. But if piles of sweaty (汗水浸湿的) T-shirts and

smelly socks drive you crazy, then two Chinese scientists might have the answer.

    Long Mingce and Wu Deyong of Shanghai Jiao Tong University have invented a kind of cotton that

cleans itself. No need for soap or water, the scientists say. All you have to do is put the clothes out in the

sun.

    According to the Guardian, this magical self-cleaning ability comes from a special chemical mixture.

The material is covered with this mixture. It can break down dirt and remove bad smells after only a few

hours in the sun.

    One of the chemicals is called titanium dioxide (二氧化钛). Scientists have known for some time that

titanium dioxide can clean fabrics (织物). However , it only works under ultraviolet (紫外的) light and so

is not yet widely used - ultraviolet light cannot be seen.

   "We knew that self-cleaning cotton fabrics with titanium dioxide coating had already been developed,

but they cannot work, or they work weakly, under sunlight," Long said. "If we want to use the fabrics in

daily life, we must develop cotton that cleans itself under daylight."

   The scientists worked hard for years to find a better chemical. Finally , they added silver iodide (碘化银) into the mixture. This made the chemical reactions in sunlight faster. The new mixture is also nearly

seven times better than the former one with pure titanium dioxide at removing dirt and killing bacteria.

   The experiment was only carried out on cotton clothing. However, according to Long, the technology

can be "applied to all kinds of fabrics and their related products." It is also cheap and environmentally

friendly , he said.

   The self-cleaning material is not yet ready for the market. Scientists still need to know whether it could

harm people. Although titanium dioxide is used in some foods, it can cause health problems if it gets into

the lungs (肺). Scientists need to make sure it is safe before we can start to enjoy the benefits of this

technology .

1. Thanks to this new discovery, we will be able to clean fabrics ___ .

A. using soap and water  

B. using silver iodide  

C. using sunlight        

D. using moonlight

2. In what way is the new material better than previous materials ?

A. It works using any kind of light.  

B. It works more quickly and effectively.

C. It is widely found in nature.      

D. It can be used for all kinds of fabrics .

3. What might be a problem with the self-cleaning material ?

A. It will cause pollution.          

B. It costs too much to produce.

C. It breaks down easily in the sun.  

D. It might cause health problems

4. Which of the following statements is TRUE? 

A. There may be many other kinds of self-cleaning fabric in the future .

B. We can already buy self-cleaning clothes on the market.

C. This was the first time that scientists discovered titanium dioxide.

D. Titanium dioxide is widely used in the food industry.

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