题目

有关基因工程的叙述正确的是 （ ） A．限制性内切酶只在获得目的基因时才用 B．重组质粒的形成在细胞内完成 C．质粒都可作运载体         D．蛋白质的结构可为合成目的基因提供资料 答案：CWhen many people are worried that there are no more heroes(英雄) in the modern society（当今社会） ,two university（大学） students who lost their lives to rescue（营救）drowning(溺水的)children have shown that heroes still exist（存在）. According to（根据） the Inner Mongolia Morning Post（内蒙古晨报）, the tragedy（悲剧）occurred on the afternoon of December 14,2002 when three school students skating on a frozen (结冰的) lake in Qingcheng Park in Hohhot（呼和浩特）fell through the ice into the freezing water. More than 20 university students who happen to be near the spot（地点） immediately went to the rescue of the children, Two children were quickly rescued, but the third died. The child’s body was not found for three hours. Two of the rescuers, Liu Ye and Hao Longbiao ,also died of cold and exhaustion(筋疲力尽). The body of Hao who took the lead（ 带领）in jumping into the lake was not found until the next day.A student who was unwilling to tell his name said he and his classmates from the local college were taking photos at the lake. When they heard the children’s cries for help,, they went to the ice hole hand in hand (手拉手)to rescue the children. But the ice kept breaking, causing most of then to fall into the icy water, Local residents(居民) held mourning ceremonies(祭奠仪式)at the lake. Eight of the students were seriously affected by the freezing water and were being kept in hospital for further observation（进一步观察）, but their lives were no longer in danger. 1.. The underlined word “occurred” here means A．employed B．mixed C．guided D．happened 2... When the three school students fell into water, the university students were A．skating on the ice B．taking photos at the lake C．having a picnic D．walking along the lake 3..Which of the following is TRUE according to the passage? A．Three students died on the same day in all. B．Hao Longbiao’s body was found on December 14,2002. C．The university students didn’t think it dangerous to save the drowning children in the lake. D．Local residents were not brave in face of danger. 4.. It can be inferred（推知） that  ______________ A．people think little of （对----评价低）the two university students’ death B．the ice on the lake wasn’t strong enough to skate on C．some students regrets（后悔） for what they had done D．heroes don’t agree with（与-----一致） the steps（步调） of modern times