问题 多选题

下列实验操作中的先后顺序正确的是 (  )(选填合理选项的字母序号,答案并非唯一).

A.加热木炭和氧化铜的混合物检验气体产物,结束时先将导管从石灰水中移出,再熄灭酒精灯

B.硫、红磷、铁丝在氧气中燃烧时,先往瓶中装适量的水,后引燃可燃物

C.实验室制二氧化碳时.先向锥形瓶内添加石灰石,再向长颈漏斗内注入适量稀盐酸

D.制取氧气时,先将导管伸入倒置于水槽中的集气瓶口.再加热盛氯酸钾和二氧化锰的试管

答案

A、加热木炭和氧化铜的混合物检验气体产物,结束时先将导管从石灰水中移出,再熄灭酒精灯,可以防止水倒吸进入试管引起试管破裂,故A正确;

B、硫燃烧生成二氧化硫会污染空气,在瓶中放少量的水能吸收二氧化硫防止污染空气,红磷燃烧生成的五氧化二磷固体会污染空气,在瓶中放少量的水会吸收五氧化二磷防止污染空气,铁燃烧后的高温熔融物溅落会炸裂瓶底,在瓶中放少量的水会防止炸裂瓶底,故B正确;

C、实验室制取二氧化碳时,加入药品的顺序是先固后液,先向锥形瓶内添加石灰石,再向长颈漏斗内注入适量稀盐酸,故C正确;

D、取氧气时,得等气泡连续均匀冒出时开始收集,先将导管伸入倒置于水槽中的集气瓶口,会导致收集的气体不纯,故D错误;

故选ABC.

问答题

Washington, June 22—More than three decades after the Endangered Species Act gave the federal government fools and a mandate to protect animals, insects and plants threatened with extinction, the landmark law is facing the most intense efforts ever by the White House, Congress, landowners and industry to limit its reach.

(46) More than any time in the law’s 32-year history, the obligations it imposes on government and, indirectly, on landowners are being challenged in the courts, reworked in the agencies responsible for enforcing it and re-examined in Congress.

In some cases, the challenges are broad and sweeping, as when the Bush administration, in a legal battle over the best way to protect endangered salmon, declared Western dams to be as much a part of the landscape as the rivers they control. (47) In others, the actions are deep in the realm of regulatory bureaucracy, as when a White House appointee at the Interior Department sought to influence scientific recommendations involving the sage grouse(松鸡), a bird whose habitat includes areas of likely oil and gas deposits.

Some environmentalists readily concede that the law has long overemphasized the stick (处罚 )and provided fewer carrots(奖励) for private interests than it might. But some of them also fear that the law’s defects will be used as a justification for a wholesale evisceration(修改法案使之失去效力).

"There’s an alignment of the planets of people against the Endangered Species Act in Congress, in the White House and in the agencies," said Jamie Rappaport Clark, executive vice president of Defenders of Wildlife, a lobbying group based in Washington.

(48) On the opposite side, Robert D. Thornton, a lawyer for developers and Indian tribes in Southern California, has argued for years that the government goes too far to protect threatened species and curtails(剥夺) people’s ability to use their own land.

"I’ve raised a child and sent him through college waiting for Congress to amend the Endangered Species Act," he said. "But I do think that a lot of forces are joining now."

(49) The Endangered Species Act of 1973 set out a goal that, polls show, is still widely admired: ensuring that species facing extinction be saved and robust populations he restored.

Currently 1,264 species are considered threatened or endangered. Some, like the bighorn sheep of the Southern California mountains, have obvious popular appeal and a constituency, while others, like the Kretschmarr Cave mold beetle in South Texas, are an acquired taste.

But in the past 30 years lawsuits from all sides have proliferated. (50)And more private 1,nd, particularly in the West, has been designated critical habitat for species, potentially subjecting it to federal controls that could limit construction, logging, fishing and other activities.

A "critical habitat" designation gives the federal government no direct authority to regulate private land use, but it does require federal agencies to take the issue into account when making regulatory decisions about private development.

The conflicts are becoming sharper as the needs of newly recognized endangered species are interfering more often with the demands of exurban development.

In others, the actions are deep in the realm of regulatory bureaucracy, as when a White House appointee at the Interior Department sought to influence scientific recommendations involving the sage grouse(松鸡), a bird whose habitat includes areas of likely oil and gas deposits.

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