题目

下列关于主族元素的说法正确的是                  A．主族元素的原子核外电子最后填入的能级是s能级         B．主族元素的原子核外电子最后填入的能级是s能级或p能级       C．主族元素的最高正价等于主族的序数      D．主族元素的价电子数有可能超过最外层电子数 答案：BC阅读理解 阅读下列短文，从每题所给的四个选项中选出最佳选项。 　　Every human being, no matter what he is doing, gives off body heart. The usual problem is how to get rid of it. But the designers of the Johnstown campus of the University of Pittsburgh set themselves the opposite problem--how to collect body heat. They have designed a collection system which uses not only body heat, but the heat given off by such objects as light bulbs and refrigerators as well. The system works so well that no fuel is needed to make the campus's six building comfortable. 　　Some parts of most modern buildings--theaters and offices as well as classrooms--are more than sufficiently (足够) heated by people and lights and sometimes must be air-conditioned even in winter. The technique of saving heat and redistributing it is called“heat recovery”. A few modern buildings recover heat, but the University's system is the first to recover heat from buildings and reuse it in others. 　　Along the way, Pitt has learned a great deal about some of its producers. The harder a student studies the more heat his body gives off. Male students send out more heat than female students, and the larger a student, the more heat he produces. It is tempting to conclude that the hottest prospect for the Johnstown campus would be a hard-working overweight male genius. 1．Which of the following is true of the heating system of the Johnstown campus? The heat is supplied by _____. [　　] A．human bodies, other heat sending objects, and fuel B．both human Bodies and other heat sending objects C．both human bodies and fuel D．human bodies 2．The technique of heat recovery is used _____. [　　] A．to produce a special form of air-conditioning B．to provide heat for the hot water system C．to find out the source of heat D．to collect and reuse heat 3．Which of the following persons would produce the least amount of heat? [　　] A．A thin male who studies hard. B．A fat female who studies hard. C．A fat male who does not study hard. D．A thin female who does not study hard. 4．The words“the hottest prospect”(last paragraph) refer to _____. [　　] A．the person who suffers most from heat B．the person who produces most heat C．the person who uses most heat D．the person who takes in heat