问题 单项选择题

水质性状指标COD可用于

A.直接反映氧含量

B.间接反映氧含量

C.直接反映有机物含量

D.间接反映有机物含量

E.反映可生物降解的有机物含量

答案

参考答案:D

解析:COD是化学耗氧量。其基本操作是在水样中人为地加入足够量的强氧化剂,经过一定时间的煮沸,使强氧化剂氧化水中有机物。每升水样中消耗掉强氧化剂的量,即为COD。水中有机物多,COD就高。可见,COD是间接反映有机物的含量,并不是直接测定有机物的含量。

单项选择题
阅读理解

Aria Ricardo was a beautiful, slim young woman with dark hair, dark eyes, and dark skin.She used to work as a model and earn as much as $ 2 000 in one day in front of the camera.She modeled for top magazines in Paris, Rome, Tokyo, and throughout the United States.

Aria’s father, now retired because of a disability, was a police officer who really loved his work.Aria would rather follow in her father’s footsteps than pursue her modeling career.She remembered listening to her father tell stories when he came home after a day on the beat.The excitement, tensions and risks of police work appealed to her.

Aria got started in the modeling business quite by accident.She accompanied a friend to an interview at a modeling agency.Her friend wanted the job, while Aria didn’t.The people at the agency were impressed with Aria’s appearance and poise.They knew she’d be brilliant in front of the camera.So they sent her on her first modeling job—for Seventeen Magazine—right away.

Despite her success as a model, Aria never gave up her dream of being a police officer.She passed the written exam for the New York Police Department.She planned to enter the Police Academy as quickly as possible.Her family and friends thought she was out of her mind even to consider such a thing.Police work was dangerous and the pay couldn’t compare to a top model’s income.But Aria knew what she wanted, and she went for it.She had never really intended to be a model anyway.Finally she hooked her fish.

56.Aria’s success as a model resulted from ________.

A.her desire to succeed in it                                               B.her looks and shape

C.the help of her father                                             D.the competition with her friend

57.Aria went into modeling because ________.

A.she wanted to earn more money                         B.she wanted to accompany her friend

C.she was given an unexpected opportunity        D.she was very beautiful

58.Aria’s family would like her to ________.

A.remain a model                                                         B.do whatever she liked

C.find something challenging                                    D.follow her father’s footsteps

59.Aria Ricardo probably is a ________ now.

A.photographer working for a magazine               B.student of the Police Academy

C.top model of a world company                             D.woman police officer