等标污染负荷考虑了污染物的（）。A.排放量 B.慢性毒作用阈浓度 C.排放标准 D.

某施工单位承建一居民楼，现浇混凝土框架结构，自拌C30混凝土，内隔墙采用加气混凝土砌块双坡屋面，防水材料为3mm厚SBS防水卷材，外墙为玻璃幕墙。生产技术科编制了安全专项施工方案和环境保护方案。一层混凝土浇捣时，项目部对现场自拌混凝土容易出现强度等级不够的质量通病，制定了有效的防治措施。一层楼板混凝土浇筑完毕后，质检人员发现木工班组不按规定拆模。

该工程屋面的卷材防水的基层应作为圆弧的有（）。

A．烟囱

B．檐口

C．前坡面

D．屋脊

E．后坡面

前列腺触诊发现前列腺肿大质硬，表面有结节，应考虑为（）

A.良性前列腺肥大

B.急性前列腺炎

C.前列腺结核

D.前列腺癌

E.前列腺增生

.Life gets noisier every day and very few people can be free from noise of some sort or another. It doesn't matter where you live--in the middle of a modern city, or a faraway village--the chances are that you' 11 be disturbed by jet planes, transistor radios, oil - powered engines, etc. We seem to be getting used to noise, too. Some people feel quite lonely without background music while they' re working.

Scientific tests have shown that total silence can be a very frightening experience for a human being. However, some people enjoy listening to pop music which is very loud, and this can do harm to their eardrums(耳鼓). The noise level in some discos is far above the usual safety level for heavy industrial areas.

One recent report about noise and concentration(专心) suggested that although a lot of people say that any noise disturbs their concentration, what really influences their ability to concentrate is a change in the level of noise. It goes on to say that a background noise which doesn't change too much(music, for example) may even help people to concentrate.

56. According to this passage, the noise pollution __

A. has become the worst in the countryside  B. has become better in big cities

C. has spread from cities to villages      D. has been controlled in modern cities

57. What does background music refer to?

A. Music played while people are working.   

B. Music played in the backyard.

C. Noise that continues while you' re listening to other noises.

D. Music used to help people to concentrate.

58. Some people have their hearing harmed __

A. while listening to pop music            B. in complete silence

C. when speaking loudly                  D. while watching TV

59. Which of the following isn't included among the things causing noise?

A. trucks           B. motorcycles   C. electric engines   D. jet planes

60. Scientists have discovered that what prevents people from concentrating on something is

A. all kinds of noise                   B. great changes in the level of noise

C. background noise                  D. popular music          

有“小太阳”美称的是（）。

A．氙灯

B．自整流高压汞灯

C．外整流式高压汞灯

D．高压钠灯

什么是行包正运率？