题目内容

U103Directions: Complete the following passage with words chosen from this unit. The initial letter of each is given.My mother and I always enjoyed our chat together under a pine tree in the park. At our 1) r__________ meeting, however, her pale face took me by 2) s____________, I asked her what was wrong, and her 3) s____________ look and silence made me believe that she was keeping something from me. Apparently, something serious was 4) d______________ her. At first, he remained silent. Finally, after my persistent 5) i_____________, she could not hold it any longer and 6) a____________ to me that she had a very serious heart disease. It suddently 7) o____________ to me that 3 years ago, she had heart 8) s____________ but her condition did not improve afterwards and now there were hardly any options left. I reached over and wrapped my arms tightly around my mother and cried. As we sat there that cool April afternoon soaking up the sun and smelling the fresh 9) _____________ of the grass, I had one wish in my heart that I could have more 10) g____________ with my mother in the days to come.

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烟尘烟气测试仪是用来采集( )中的气态和颗粒态污染物。

A. 环境空气
B. 有组织源
C. 无组织源
D. 大气净化设备

气袋常用的材质有聚四氟乙烯、聚乙烯、聚氯乙烯和金属衬里气袋等,它适用于采集化学性质稳定、不与气袋起化学反应的低沸点气态污染物。采样前气袋应清洗干净,无残留气体干扰、不漏气。采样时用现场空气清洗气袋( )次后再正式采样,采样后迅速将进气口密封。

A. 1-3
B. 3-5
C. 5-10
D. 不清洗

富集采样法适用于气体中被测物质浓度很低,或所用方法的灵敏度不高的情况,它包括 ( )

A. 溶液吸收法
B. 填充柱阻留法
C. 滤料阻留法
D. 自然积集法

富集采样法都需要使用外接动力设备,对样品进行富集采集。

A. 对
B. 错

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