题目

某款玩具电动汽车上安装有电动机和小灯泡，它们既可以各自独立工作，又可以同时工作。如图所示的电路中，符合上述要求的是A. B. C. D. 答案：【答案】D【解析】使用时，灯泡和电动机既可以独立工作，也可以同时工作，说明小灯泡L和电动机M并联，各由一个开关控制。A、电动机和小灯泡并联接入电路，开关S1为总开关，控制整个电路，开关S2控制电动机，电动机不能独立工作，故A错误；B、电动机和小灯泡并联接入电路，开关S1为总开关，控8、In the past, scientists have produced exact genetic copies of sheep and a few other animals．They  1  these clones from a single cell of an adult animal．     Recently, a private group of scientists has announced 2  to make an exact copy of a human being．Doctor Zavos, an American member of the team, says he and  3  will soon begin to clone humans and they hope to produce the world’s first cloned  4 within the next two years．     Doctor Zavos says the new  5  group plans to offer human cloning to women unable to become  6  and produce children．The 7  would be similar to that used to clone animals．It would  8 clearing genetic material from a woman’s egg．Doctors then would  9  genetic material from the woman’s husband into the egg  10  putting it in the women’s uterus（子宫）．     Doctor Zavos says his  11  plans to do its work in a country near the Mediterranean Sea, but he did not  12 the country． He says an Italian reproductive expert, Severino Antinori, is  13  the team．Doctor Antinori has made 14  efforts to help many older women become pregnant．He is known for  15  pregnancies in women as old as sixty．     Many medical experts and other groups  16  the idea of cloning humans． Several doctors criticized the  17 by Doctor Zavos．They say doctors do not know if cloning humans is  18  or safe．They say it would be irresponsible to  19  to clone a human being． That is because the   20  of success are too small and the risks are too great． 1．A．bought               B．created       C．discovered             D．found 2．A．plans            B．results           C．successes            D．agreements 3．A．another             B．others         C．the other            D．the others 4．A．plant                B．animal       C．bird                 D．baby 5．A．international          B．national      C．American            D．Italian 6．A．successful           B．born         C．pregnant             D．fertile 7．A．imagination           B．technology     C．story               D．symbol 8．A．involve              B．start         C．make              D．borrow 9．A．translate             B．place        C．take               D．make 10．A．after               B．while        C．before              D．on 11．A．country             B．group        C．university           D．company 12．A．call                B．found        C．name               D．consider 13．A．managing           B．running      C．controlling           D．leading 14．A．high                B．total         C．great              D．wide 15．A．successful          B．beautiful        C．thankful            D．sorrowful 16．A．take up              B．object to       C．put up             D．bring down 17．A．announcement       B．program       C．subject             D．idea 18．A．careful                     B．interesting      C．unable             D．possible 19．A．manage               B．refuse          C．attempt            D．hope 20．A．facts               B．results       C．sizes                 D．chances 评卷人 得分 二、选择题 （每空？ 分，共？ 分）