某住宅区规划分期建造，在首期建设时，某物业管理企业签订了该住宅区的物业服务合同。下列

在制剂中常作为金属离子络合剂使用的物质是

A．NaHCO3

B．Na2S2O3

C．硬脂酸

D．EDTA

E．Na2CO3

Civil Affairs and Public Security Departments have been urged to take comprehensive steps to help children who are begging on the nation's streets and are often abused. Premier Wen Jiabao said during his online chat with netizens, China Daily reported.

Wen said he has paid close attention to the ongoing micro blog campaign that calls on concerned netizens to post photos of children begging on the streets in the hope that police will rescue them and return them to their families. There are many reasons why children turn to begging, including poverty and family problems. Joint efforts will help end the problem.

His remarks were welcomed by Yu Jianrong, a professor from the Chinese Academy of Social Sciences, who starts the online campaign to crack down on child begging.

The All-China Women's Federation (ACWF) also released a statement encouraging people to contact the police if they find any suspect who abuses, or forces juveniles to beg on the streets. People can either call 110 and or dial 12338 and connect with a hotline set up by the ACWF. The statement was reported by Xinhua News Agency.

The micro blog campaign has gained support from charities, and other social institutions since it was launched in January. One Foundation, a Shenzhen-based charity, set up a fund on Feb 19 for a database for sharing information about missing children So far, One Foundation has raised 720,000 yuan ($109,500). Meanwhile, Shanghai Time Plastic Surgery Hospital has offered free plastic surgery to Ren Fangfang, an 8-year-old girl who suffered physical abuse at the hands of a man who used her to beg for him.

小题1:

Which of the following statements is TRUE according to the passage?

A．Premier Wen Jiabao chatted with Yu Jianrong online.

B．One Foundation has set up a hotline for missing children.

C．ACWF promised to offer Ren Fangfang free plastic surgery.

D．Poverty and family problems contribute to child begging小题2:

Which of the following directly take part in the campaign to help child beggars?

A．Chinese Academy of Social Sciences and China Daily

B．The All-China Women's Federation and Xinhua News Agency

C．One Foundation and Shanghai Time Plastic Surgery Hospital

D．Civil Affairs and Public Security Departments and China Daily小题3:

What’s the main purpose of the online blog campaign started by Yu Jianrong?

A．To draw the top leader’s attention to the child beggars.

B．To call for comprehensive steps from the government.

C．To gain support from charities and other social institutions.

D．To post photos of child beggars and help them go back home.小题4:

. Which word can best replace the underlined part “crack down” in Para 3?

A．punish

B．urge

C．delay

D．limit

扩声系统的系统失真术语是指（）。

A.传输频率特性：扩声系统在稳定工作状态下，厅堂内各测量点稳态声压级的平均值相对于扩声设备输入端的电平的幅频响应

B.声反馈：扩声系统中的扬声器系统放出的部分声能反馈到传声器的效应

C.系统失真：扩声系统由输入信号到输出信号全过程中产生的非线性畸变

D.混响时间：声源达到稳态，待停止发声后，室内声压级衰减60dB所需的时间

套管式冷凝器冷却水与制冷剂呈（），以增强传热效果。

压力平衡