单项选择题

城市环境指影响城市人类活动的各种自然的或人工的外部条件。城市环境保护指采取行政的、法律的、经济的、科学技术的多方面措施,合理地利用自然资源,防止城市环境污染和破坏,以及产生污染后进行综合整治。目的是保护和改善生态平衡,扩大有用自然资源的再生产,保障城市人类经济社会的发展。城市环境保护是一项综合性的事业,需要各学科、各部门的通力合作。从一般意义上说,开展城市环境保护必须对城市环境有透彻的认识,包括明确城市环境的组成、特点、城市环境效应、城市环境容量的状态、城市环境的影响因素、掌握城市环境污染的类型和特点及进行城市环境综合整治这几项工作。其中,( )又是建立在环境质量评价、制定环境质量标准、拟定环境规划的基础上。

点击查看答案

上一题目录下一题

相关考题

多项选择题
变电所综合自动化系统应当满足几个方面的要求（）。

A.适用性
B.安全性
C.可靠性
D.先进性及灵活性
多项选择题
下列为发电机主保护（）。

A.纵差保护
B.低频减载
C.过负荷
D.失磁保护
单项选择题
The Frontier and the Family The impact (影响) of the frontier has been traditionally assumed by historians, who have studied its effects on mountain men and cowboys, political and social institutions. Yet the impact of the frontier on the most common dimension of life—upon the family—remains largely unexamined. Although family has been especially significant in the historical process, it is a relatively new area of historical research. In terms of westward migration, family played a special role. For a people who mistrusted the church as much as the state, family was the only institution that could be entrusted with the enterprise of settling the continent. A Christian family was enough of the church; a Christian family was sufficient expression of political and social order. In 1862, Congress provided for the distribution of lands to heads of households in a law, but that law merely recognized that settlement had been the business of families since the seventeenth century. Families took up the challenge of the western lands in a variety of ways. Some families moved west in loosely organized groups made up of families in similar directions. They drew up constitutions and elected leaders and generally applied the democratic process to the journey west. The government, for its part, provided little help — no maps or transportation, no tools or agricultural information, no medical services and little protection. Beyond the westward-running rivers there was no road until wagons left deep tracks on the ground so that one could see a trail — or until enough wagons became lost and doubled back to warn others against their mistakes. Nonetheless, the attraction of 'free land' was irresistible. One day or another, in a wagon train or all alone, a family packed its belongings and its livestock and set off toward the next 'empty' space.In the author's opinion, the role played by the family _________.A．received little attentionB．was insignificant, if compared with the impact of the frontier on cowboysC．was not so important as the church or the stateD．was overlooked completely

A.
B.
C.
In
D.
A．received
E.was
F.was
G.was