题目

右图装置常用来测定空气中氧气的含量。下列对该实验的认识中正确的是A. 红磷燃烧产生大量白色烟雾B. 燃烧匙中的红磷可以换成细铁丝C. 该实验可说明N2难溶于水D. 红磷的量不足会导致进入集气瓶中水的体积大于1/5 答案：【答案】C【解析】A红磷燃烧时发出黄光，产生大量的白烟。因为生成的五氧化二磷状态是固态。所以描述是用烟。此项错误。B测定空气中的氧气含量，不能用铁，因为铁在空气中不能燃烧，铁只有在氧气浓度较大时才能燃烧。此项错误。C该实验能够说明氮气不溶于水，不燃烧也不支持燃烧。此项正确Astronomers (天文学家) say they are on the point of finding planets like Earth orbiting other stars, which is a key step in determining if we are alone in the universe. A top NASA official and other leading scientists say that within four or five years they should discover the first Earth-like planet where life could develop, or may have already. A planet close to the size of Earth could even be found sometime this year. At the annual American Astronomical Society conference this week, each discovery involving  so-called “exoplanets” —those outside our solar system — pointed to the same conclusion：Quiet planets like Earth where life could develop probably are plentiful. NASA’s Dew Kepler telescope and a lot of new research from the suddenly hot and competitive exoplanet field caused noticeable buzz at the meeting．Scientists are talking about being at “an incredible special place in history” and closer to answering the question. “Are we alone? For the first time, there’s an optimism that sometime in our lifetimes we’re going to get to the bottom of that,” said Simon Worden，an astronomer who heads NASA’s Ames Research Center. “If I were a betting man, which I am, I would bet we’re not alone.” “These are big questions that reflect upon the meaning of the human race in the universe,” the director of the Vatican Observatory, the Rev. Jose Funes, said Wednesday in an interview at this week’s conference. Worden told The Associated Press: “I would certainly expect in the next four or five years we’d have an Earth-sized planet in the habitable (可居住的) zone.”【小题1】What is very important in determining if we are alone in the universe?A．Finding an Earth-like planet B．Orbiting other stars. C．Developing new telescopes D．Finding more exoplanets. 【小题2】What’s an exoplanet?A．It’s a planet like Earth B．It’s a planet outside our solar system. C．It’s a planet orbiting the sun D．It’s a planet where life have developed. 【小题3】The underlined phrase “get to the bottom of” probably means “__________”.A．understand fully B．make full use of C．search for D．do more research on 【小题4】From the passage we can learn that __________. A．an Earth-like planet has been found B．it’s been proved we are not alone in the universe C．Jose Funes has found the meaning of the human race in the universe D．the discovery of an Earth-like planet could happen in the near future