国内精品一区二区三区最新_不卡一区二区在线_另类重口100页在线播放_精品中文字幕一区在线

Home
Letters to Editor
Domestic
World
Business & Trade
Culture & Science
Travel
Society
Government
Opinions
Policy Making in Depth
People
Investment
Life
Books/Reviews
News of This Week
Learning Chinese
Schools Urged to Protect Environment During Chemistry Experiments

Chemistry is a required course for middle-school students, but some experts are calling on the 258 middle schools in Harbin to be more careful about draining off chemical wastewater created in experiments, which they say is polluting the environment.

It is a new problem in environmental protection, said a chemical teacher for Harbin First Middle School whose surname is Xi when interviewed with Harbin Daily. Some materials used in senior middle-school students? organic experiments, such as phenol and bromobenzene, are poisonous. Benzene is a known carcinogenic. Some labs in middle schools have no means of direct disposal of experimental wastes, and disposal machines are expensive.

A chemical teacher in Harbin Sixth Middle School also thinks the school can do nothing in regard to laboratory pollution. He said if one class conducts chlorine experiments, the whole school fills with the smell of chlorine. And the smell of sulfur dioxide is more unpleasant. According to another teacher, although the school is a key school, its laboratories have no recycling equipment for wastewater that is poured into the sewer -- let alone what goes on in ordinary schools

Middle-school students need to conduct many experiments, according to teaching programs, and half of them involve acidic or alkaline reactions that are poisonous. With dense acids and alkali, teachers ordinarily pour them into specific containers for other experiments or to wash containers. They pour the liquid into sewers after it has become less poisonous. Some schools bury corrosive and dangerous wastes. As gases are not easy to reclaim, some teachers reduce their pollutions through acid-base neutralization. A few schools are equipped with ventilation machines to pump out poisonous gases, but this only transfers pollutants to other places.

Fan Qingxin, professor for the Environmental Engineering School of Harbin Institute of Technology and an expert in laboratory environment protection, said school laboratories are contributing much harm to the environment since many sewers link directly to rivers in Harbin. Even if the chemical wastewater soaks into the earth, the pollution to the environment is tremendous. Foreign schools all have special recycling programs, which need funds but are required. And delivering laboratory wastes to special places for treatment is a basic social responsibility.

Fan advised middle schools to do harmless experiments to protect environment. He added that schools should pay more attention to the construction of laboratories and the training of lab assistants. Environmental protection departments can also ask chemistry departments to collect experiment wastes. In a word, he said, creating pollution should not be a by-product of any study to further knowledge.

(Yue Tongming for 新华网 [Xinhua News Agency] January 21, 2002 translated by Feng Yikun for china.org.cn)


'10th Five-year Plan' for National Environmental Protection Approved
Environment-Friendly Lifestyle Fashionable
Urban Wastewater Treatment Offers Chances for Overseas Business
10 New Sewage Treatment Plants Operational in Central China
Public Awareness, Key to Environmental Protection
UN Calls for Greater Efforts to Protect Environment
Environment Proves to Be Top Public Consideration
16 Receive National Environmental Award
WB Gives Suggestions on China's Environmental Protection
Copyright © China Internet Information Center. All Rights Reserved
E-mail: webmaster@china.org.cn Tel: 86-10-68996214/15/16
国内精品一区二区三区最新_不卡一区二区在线_另类重口100页在线播放_精品中文字幕一区在线
久久国产夜色精品鲁鲁99| 欧美一区二区三区公司| 一区二区日韩电影| 制服丝袜亚洲精品中文字幕| 看电视剧不卡顿的网站| 中文字幕av一区 二区| 日韩一区二区三区免费看| 久久这里只有精品首页| 99久久夜色精品国产网站| 亚洲成人一二三| 国产亚洲婷婷免费| 欧美日韩综合在线免费观看| 久久激五月天综合精品| 18成人在线观看| 日韩一区二区电影| 99精品视频在线观看免费| 日韩黄色免费网站| 亚洲欧洲99久久| 色综合久久天天| 亚洲另类春色国产| 久久亚洲欧美国产精品乐播 | 最新中文字幕一区二区三区| 欧美日本一区二区在线观看| 国产一区美女在线| 婷婷综合在线观看| 国产精品久久久久影院| 日韩精品中文字幕一区| 国产日韩综合av| 韩国精品久久久| 午夜日韩在线电影| 成人免费一区二区三区在线观看| 在线不卡的av| 欧美中文字幕不卡| eeuss影院一区二区三区| 久久99久久99小草精品免视看| 日韩伦理电影网| 国产无一区二区| 日韩精品一区二区三区在线观看| 色诱亚洲精品久久久久久| 国产精品88av| 国精品**一区二区三区在线蜜桃| 亚洲成人高清在线| 一区二区三区四区高清精品免费观看 | 一区二区三区四区不卡视频| 国产视频视频一区| 亚洲人成网站在线| 国产一区二区不卡| 麻豆传媒一区二区三区| 亚洲成a人片综合在线| 国产一区不卡精品| 国产日本欧美一区二区| 精品国产网站在线观看| 欧美一区二区视频观看视频| 在线精品视频免费播放| 在线观看日韩毛片| 在线欧美日韩精品| 欧美制服丝袜第一页| 一本到一区二区三区| 99国产一区二区三精品乱码| 成人一区二区视频| 粉嫩绯色av一区二区在线观看| 国内不卡的二区三区中文字幕 | 久久久精品tv| 成人高清免费在线播放| 成人免费黄色在线| eeuss影院一区二区三区| 成人av网站在线观看| 9人人澡人人爽人人精品| 成人av午夜影院| 91麻豆国产香蕉久久精品| 99久久99精品久久久久久| 久久婷婷国产综合精品青草| 成人免费的视频| 色综合久久中文综合久久97| 欧美性受xxxx黑人xyx| 欧美色网站导航| 91麻豆精品国产91久久久 | 久久精品久久精品| 精品一区二区久久| 国产91色综合久久免费分享| 成人高清视频免费观看| 91美女片黄在线观看91美女| 色琪琪一区二区三区亚洲区| 欧美日本一道本在线视频| 91精品国产色综合久久不卡电影 | 欧美大片日本大片免费观看| 久久久影视传媒| 一区二区中文视频| 爽爽淫人综合网网站| 九一九一国产精品| jlzzjlzz亚洲女人18| 欧美性三三影院| 亚洲同性同志一二三专区| 26uuu精品一区二区三区四区在线| 国产精品嫩草影院av蜜臀| 亚洲综合另类小说| 激情小说亚洲一区| 一本一本久久a久久精品综合麻豆 一本一道波多野结衣一区二区 | 日韩中文字幕一区二区三区| 激情偷乱视频一区二区三区| 91美女片黄在线观看91美女| 欧美一区二区三区的| 欧美激情一区二区三区全黄| 亚洲小少妇裸体bbw| 精品在线视频一区| 91黄色在线观看| 欧美精品一区二区在线观看| 久久久综合激的五月天| 成人avav在线| 日韩欧美亚洲另类制服综合在线| 国产亚洲一区二区三区四区 | 91久久精品一区二区三区| 日韩免费视频一区| 亚洲精品久久7777| 欧美性猛交xxxx乱大交退制版 | 欧美高清你懂得| 中文字幕色av一区二区三区| 青青国产91久久久久久| 91美女在线观看| 国产免费观看久久| 美女视频黄 久久| 91福利在线导航| 国产精品污网站| 精品无人区卡一卡二卡三乱码免费卡| 99精品久久99久久久久| 久久久久久综合| 免费不卡在线观看| 欧美色图12p| 亚洲视频一区在线| 国产·精品毛片| 欧美mv日韩mv国产网站| 欧美大片在线观看一区| 亚洲一区二区三区美女| 91一区二区在线观看| 2021国产精品久久精品| 日本亚洲电影天堂| 欧美精品一二三四| 亚洲在线中文字幕| 一本一道综合狠狠老| 18成人在线视频| 欧美日韩国产一区二区三区地区| 国产盗摄精品一区二区三区在线 | 精品av综合导航| 日本视频一区二区三区| 欧美日韩一区精品| 亚洲第一会所有码转帖| 色久优优欧美色久优优| 亚洲欧美电影一区二区| 99精品欧美一区| 一区二区三区中文字幕在线观看| 99在线精品一区二区三区| 国产精品理论片在线观看| 粉嫩av一区二区三区在线播放| 久久午夜色播影院免费高清| 狠狠久久亚洲欧美| 久久夜色精品一区| 岛国精品在线观看| 欧美影视一区二区三区| 亚洲综合色视频| 欧美日本乱大交xxxxx| 污片在线观看一区二区| 日韩一级精品视频在线观看| 免费高清在线视频一区·| 欧美zozo另类异族| 国产九色sp调教91| 亚洲欧洲日韩女同| 欧美做爰猛烈大尺度电影无法无天| 午夜欧美2019年伦理| 欧美亚洲国产一区二区三区va| 亚洲成av人片一区二区梦乃| 欧美疯狂做受xxxx富婆| 韩国女主播成人在线观看| 国产欧美视频一区二区| 色综合久久久久综合99| 香蕉成人啪国产精品视频综合网| 日韩写真欧美这视频| 国产激情91久久精品导航| 中文字幕日本乱码精品影院| 欧美在线观看禁18| 另类综合日韩欧美亚洲| 国产精品女同一区二区三区| 国产乱人伦精品一区二区在线观看| 日韩免费看的电影| 成人免费毛片高清视频| 亚洲一区二区精品久久av| 日韩欧美成人激情| 成人av电影免费观看| 天堂成人国产精品一区| 成人高清在线视频| 亚洲无人区一区| 久久久三级国产网站| 日本精品一区二区三区四区的功能| 性做久久久久久免费观看欧美| ww久久中文字幕| 在线视频一区二区三区| 国产在线视频不卡二| 一区二区三区精品在线观看| 精品少妇一区二区三区在线视频| 亚洲欧洲精品一区二区精品久久久| 免费观看久久久4p|