湖泊完全混合衰减模式常用于各种湖库的水质模拟预测,其可分为( )。A.动态模式 B

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问题:

湖泊完全混合衰减模式常用于各种湖库的水质模拟预测,其可分为( )。

A.动态模式

B.准动态模式

C.完全混合模式

D.平衡模式

考点:环境影响评价工程师环境影响评价技术导则与标准环境影响评价技术导则与标准
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海岸线曲折,多峡湾与岛屿,海湾常深入内陆而两岸陡峭。以上是某种地质作用形成的海岸景观,据此完成下列问题。

(1)下列哪一种地区的海岸可以看到这种景观(  )

A.中国东部                                B.大洋洲南部

C.英国北部                                D.智利中部

(2)形成该种海岸的地质作用和北美洲哪一项自然地理特征形成原因相似(  )

A.疆域广大,气候差异大

B.河流呈放射状,且源远流长

C.东西两大山脉大致为南北走向

D.中央大平原北部湖泊星罗棋布

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重力灌浆仅靠()灌入缝隙,()加压力。

A、大气压力

B、浆液自重

C、适当

D、不

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On the first Earth Day, the U.S. was a poisoned nation. Dense air pollution blanketed cities like Los Angeles, where smog alerts were a fact of life. Dangerous pesticides like DDT were still in use, and water pollution was rampant—symbolized by raging fires on Cleveland’s Cuyahoga River. But the green movement that was energized by Earth Day— and the landmark federal actions that followed it—changed much of that. Today air pollution is down significantly in most urban areas, the water is cleaner, and even the Cuyahoga is home to fish again.

But if the land is healing, Americans may be sickening. Since World War Ⅱ, production of industrial chemicals has risen rapidly, and the U.S. generates or imports some 19 billion kg of them per day. These aren’t the sorts of chemicals that come to mind when we picture pollution—huge plants spilling contaminated wastewater into rivers. Rather, they’re the molecules that make good on the old "better living through chemistry" promise, appearing in items like unbreakable baby bottles and big-screen TVs. Those chemicals have a, habit of finding their way out of everyday products and into the environment—and ultimately into living organisms. A recent biomonitoring survey found traces of 212 environmental chemicals in Americans—including toxic metals, pesticides, etc. "It’s not the environment that’s contaminated so much," says the director of the Cincinnati Children’s Environmental Health Center. "It’s us."

As scientists get better at detecting the chemicals in our bodies, they’re discovering that even tiny quantities of toxins can have a potentially serious impact on our health—and our children’s future. Chemicals like bisphenol A (BPA) and phthalates—key ingredients in modern plastics—may disrupt the delicate endocrine system. A host of modern ills that have been rising unchecked for a generation—obesity, diabetes, attention-deficit disorder —could have chemical connections. "We don’t give environmental exposure the attention it deserves," says Dr. Philip Landrigan. "But there’s an emerging understanding that kids are uniquely susceptible to environmental hazards."

Washington has been slow to arrive at that conclusion. The Toxic Substances Control Act (TSCA), the 34-year-old vehicle for federal chemical regulation, has generally been a failure. The burden of proving chemicals dangerous falls almost entirely on the government. And the Environmental Protection Agency (EPA) has been able to issue restrictions on only a handful of chemicals and has lacked the power to ban even some dangerous cancer-causing substances.

But change is coming. The Obama Administration is taking a closer look at chemicals. More important, Congress may finally be ready to act. "We can’t permit this assault on our children’s health—and our own health—to continue," says Senator Frank Lautenberg.

According to Senator Frank Lautenberg, ()

A. actions should be taken to protect children from the environmental chemicals

B. more people begin to realize children’s susceptibility to environmental hazards

C. we should give more attention to environmental exposure

D. it’s more important and urgent to protect children’s health

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电网的电压质量取决于电力系统中()的平衡。

A.视在功率

B.无功功率

C.有功功率

D.额定功率

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地质环境具有开放与封闭的两重性

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