单选题 The use of nitrous oxide, or laughing gas during childbirth fell out of favor in the United States decades ago, and just two hospitals—one in San Francisco and one in Seattle—still offer it. But interest in returning the dentist office staple to the delivery room is growing: respected hospitals including Dartmouth-Hitchcock Medical Center plan to start offering it, the federal government is reviewing it, and after a long break, the equipment needed to administer it is expected to hit the market soon.
Lori Rowell, due to give birth to her second child in June, is interested in the option.
"I would definitely think about it, and read about and talk to my doctor about it," said Rowell, 36, of Concord. "It is nice to know that it doesn"t affect the baby."
Though laughing gas is commonly used for labor pain relief in Canada, Great Britain and other countries, it"s been all but abandoned in the United States in favor of other options, said Judith Bishop, a certified nurse midwife at the University of California San Francisco Medical Center and leader in the effort to reintroduce laughing gas for labor.
"In this country, most people when they hear about laughing gas, they think it sounds pretty retro (重新流行的), that it sounds very old-fashioned and they"re sure there"s something bad or dangerous about it and we must"ve chosen to eliminate it. But I think we eliminated it because we went for the more specialized, higher-tech options," said Bishop, who will be among the speakers Monday at a conference for New Hampshire, Vermont and Maine hospital officials.
She and other advocates of reintroducing laughing gas emphasize that it is no silver bullet—it "takes the edge off" pain rather than eliminates it. But they say it should be among the options offered to women, particularly those who give birth at small or rural hospitals that lack round-the-clock anesthesiologists (麻醉师). Laughing gas is easy for women to self-administer, takes effect quickly, and can be used late in labor.
"It"s not fight for everybody, but it"s something that for many women will offer a certain amount of relief," Bishop said.

单选题 Dartmouth-Hitchcock Medical Center is going to ______.

【正确答案】 C

【答案解析】[解析] 根据专有名词Dartmouth-Hitchcock Medical Center定位到第1段第2句。该句中的return...to...表明包括Dartmouth-Hitchcock Medical Center在内的一些著名的医院都将把常用于牙科的笑气用到产科去。这意味着，笑气将再次用于产科，故应选C。该句中的return...to...只表明人们想在产房再次使用笑气，并非指在牙科中不再使用笑气，故B错误。

单选题 According to Judith Bishop, laughing gas was abandoned in the United States mainly because other options are ______.

【正确答案】 D

【答案解析】[解析] 第5段第2句提到当年淘汰笑气的原因是其他技术more specialized，higher-tech options，故可知与其他麻醉剂或止痛药相比，笑气不够“专业”，不够“高科技”，故应选D。由该句中的But可知，Bishop并不认同前面所说的“笑气存在危险”这个理由，因此排除A；本题最具干扰性的是B。第5段并没有在“有效性”方面对比笑气和后来研发的麻醉剂或止痛药，虽然原文提到笑气不够先进，但不能因此推断它药效不够好，事实上，第6段最后一句提到的takes effect quickly表明笑气能很快产生药效，这也是effective的表现之一，可见B不正确。

单选题 By saying that "it is no silver bullet" (Para. 6), Judith Bishop means that ______.

【正确答案】 A

【答案解析】[解析] 第6段第1句中破折号后面的内容解释说明not silver bullet的含义。rather than表明，笑气可以减轻痛楚，但不能消除痛楚，A“不能消除痛楚”与之相符，故为本题答案。silver bullet指“灵丹妙药；特效药”，takes the edge off意为“减轻”。原文并没有提到笑气能多大程度上减轻痛楚，不能武断地说笑气“不能减轻多少痛楚”，故B不正确。

单选题 As it is suggested in the passage, laughing gas can NOT be used properly ______.

【正确答案】 B

【答案解析】[解析] 第1段最后一句中的the equipment needed to administer it表明笑气的使用必须要依靠专用的仪器，由此可知，没有这种仪器，笑气就不能使用，故应选B。第6段第2句暗示没有全天候的麻醉师的医院很适合使用笑气，因此A不符合题意；该段最后一句中的self-administer表明笑气设备可以由产妇自己控制，故C、D均不符合题意。