燃气管道及其附件组装完成并试压合格后，应进行通球扫线，并不少三()次。A．2 B．3 发布时间：2017-02-26 21:39 │ 来源：www.tikuol.com 题型：单项选择题 问题： 燃气管道及其附件组装完成并试压合格后，应进行通球扫线，并不少三()次。A．2B．3C．4D．5
题型：单项选择题 慢性喘息性支气管炎见A．呼气性呼吸困难，双肺满布哮鸣音B．端坐呼吸，双肺底水泡音C．呼气性呼吸困难，两肺散在干湿性啰音D．发热、咳嗽，夜间阵发性气急，肺无异常体征E．进行性呼吸困难，咳嗽，痰中带血 查看答案
题型：单项选择题 根据《中华人民共和国大气污染防治法》规定：( )排污单位，必须采取措施防止周围居民区受到污染。A．向大气排放气体和气溶胶的 B．向大气排放气体的C．向大气排放恶臭气体的 D．向大气排放气溶胶的 查看答案
题型：单项选择题 Passage TwoWith unemployment rising and housing costs still high, cities around the country are experiencing a new and sudden wave of homelessness. Shelters are overflowing, and more people this year are sleeping on floors in dingy social service centers, living in cars or spending nights on the streets. In New York, Boston and other dries, homelessness is at record levels, a consequence of a faltering (摇晃的) economy that has crumbled even further after the Sept. 11 attacks. A survey by the U. S. Conference of Mayors released last week found that requests for emergency shelter in 27 cities had increased an average of 13 percent over last year. The report said the increases were 26 percent in Trenton; 25 percent in Kansas City, Mo.; 22 percent in Chicago; 20 percent in Denver; and 20 percent in New Orleans. An unusual confluence of factors seems to be responsible for the surge. Housing prices, which soared in the expansion of the 1990’s, have not gone down, even though the economy has tumbled. A stream of layoffs has newly unemployed people taking low-wage jobs that might have otherwise gone to the poor. Benefits for welfare recipients are expiring under government imposed deadlines. And charitable donations to programs that help the disadvantaged are down considerably, officials around the country said, because of the economy and the outpouring of donations for people affected by Sept. 11. "This is an unprecedented convergence (集中) of calamities (灾难) ," said Xavier De Souza Briggs, an assistant professor of public policy at the John F. Kennedy School of Government at Harvard. "It’s really a crisis. " More than half the cities surveyed by the mayors’ group reported that in the last year people had remained homeless longer, an average of six months. There is no total number for the homeless nationwide. Experts said it was difficult to compare the situation with statistics in previous decades, because counting methods have improved. Yet, several experts said they believed that the increases reported by cities like Boston and Chicago reflected a national trend. "My impression is there is more homelessness now than there was 20 years ago," Gary Burtless, an economist at the Brookings Institution, said, adding that he believed that economic factors were not the sole explanation. "I think that there must be a greater segment of our population that has tenuous connections to family and friends, and therefore has fewer resources to fall back on when something very bad happens like when they lose their job," he said.According to economist Gary Burtless, What factor accounts for the surge of homeless apart from the economic explanationA．Political.B．Social.C．Religious.D．International. 查看答案