1999年3月15日,美国军方在新墨西哥州白沙导弹靶场,成功地进行了PAC一3型“爱

题型:单项选择题

问题:

1999年3月15日,美国军方在新墨西哥州白沙导弹靶场,成功地进行了PAC一3型“爱国者”导弹拦截战术弹道导弹试验,标志着美国在发展高性能战区导弹防御系统上又取得了新的进展. PAC一3型“爱国者”导弹是采用动能武器技术发展起来的一种新概念防空反导武器,可在大气层内低空、靠直接碰撞杀伤方式拦截摧毁战术弹道导弹,以保护像指挥控制中心、港口和地下井之类的重要军事目标.目前,它正处于型号研制阶段. PAC一3型“爱国者”导弹由一级固体助推火箭、制导设备、雷达导引头、姿态控制与机动控制系统、杀伤增强器等组成.全弹长5.2米,弹体直径255毫米,起飞重量321千克,助推火箭关机后的重量为140千克.其雷达可在导弹飞行末端自主跟踪与识别来袭目标,既可跟踪战术弹道导弹,也可跟踪巡航导弹和飞机,具备较强的抗干扰能力和高机动能力.其姿态控制发动机由180台径向分布、快速点火的微小型脉冲式固体发动机组成,在导弹飞行末端,控制弹体的俯仰与偏航,修正姿态,确保导弹灵活机动、自主寻的,直接命中摧毁目标.杀伤增强器是为该导弹专门设计的一种补拦设备,用来增大导弹的有效拦截面积,降低脱靶率.它由24块每块重214克的破片和炸药组成,当导弹在接近目标达一定距离时,雷达导引头测距数据决定准确及时引爆炸药,使动24片破片围绕弹体中心低速径向发射出去,形成高密度的破片圆环,有效增大拦截面积,使敌方导弹或被导弹击中或被破片击中. PAC一3型“爱国者”导弹对战术弹道导弹的拦截距离达40千米,拦截高度达15千米,可拦截射程小于l000千米的战术弹道导弹.其主要特点是:综合作战能力强,杀伤威力大,与来袭弹头碰撞时的质量可达140千克,可形成巨大动能,确保摧毁目标;同时,它尺寸小,机动灵活,火力大,在一部只能装4枚海湾战争用“爱国者"导弹的发射车上,可带16枚PAC一3型“爱国者”导弹;另外,其作战条件范围广,具备全天候作战能力,可在大气层内低空作战,在雾、雪、雨和预计不到的对抗环境下都有效.

根据第一自然段内容表述正确的一项是_______.

A.1999年3月15日,PAC一3型“爱国者”导弹试验成功,标志着美国在发展高性能导弹防御系统上又取得了新的进展

B.1999年3月15日.PAC一3型“爱国者”导弹试验成功,标志着美国在发展高性能战区导弹防御系统上取得了新的进展

C.1999年3月15日,PAC一3型“爱国者”导弹试验成功,标志着美国在高性能战区导弹防御系统上又取得了新的进展

D.1999年3月15日,PAC一3型“爱国者”导弹试验成功,标志着美国在发展高性能战区导弹防御系统上再次取得新的进展

考点:在职联考GCT(语文)GCT(语文)57
题型:单项选择题

第二部分:阅读理解(共两节,满分40分)

第一节(共15题;每小题2分,满分30分)

阅读下列短文,从每题所给的四个选项(A、B、C和D)中,选出最佳选项,并在答题卡上将该项涂黑。

If you are looking for a new pet, don’t even think about Komodo dragons, which are the largest lizards and can grow to be 10 feet long and weigh more than 300 pounds. Komodo dragons run fast and eat almost any kind of meat, including dead or live animals, other Komodo dragons and people. “These things are powerful killing machines,” says Bryan Fry, a biologist.

If those reasons aren’t good enough, consider the bite of a Komodo dragon. According to a new study, it may kill prey like snakes by injecting venom. This chemical, according to Fry and his team of scientists at the University of Melbourne in Australia, can cause shock in the unlucky victim. A person or animal goes into shock when the body can’t offer enough blood to organs to keep functioning. As a result, the body starts to shut down.

Scientists have only recently begun to understand why a Komodo dragon is so deadly. Some people used to believe that a Komodo dragon’s bite contained bacteria from the mouth that would cause a severe infection in the victim’s blood. The infection would finally kill the animal. Fry says that after being bitten by a Komodo dragon, animal usually die quickly.

After more studies, Fry and his team found that Komodo dragon venom contained some of the same ingredients as snake venom. These ingredients thin the blood and cause blood vessels to become larger. To test the venom, the scientists injected rats with it and observed that the rats became still.

Fry’s work shows that Komodo dragons kill their prey with venom, and not by bacteria — and gives us another reason why we should avoid coming across them. That is easy to do, since they live on a few islands in the tropical country of Indonesia.

41. From the passage we can learn that ______.

A. Komodo dragons live on a few islands of India

B. a Komodo dragon weighs more than 300 kilograms

C. a Komodo dragon is more than eleven feet long

D. nobody dares to keep a Komodo dragon as a pet

42. The underlined word “venom” in Paragraph 2 probably means ______.

A. the chemical that does no harm  

B. a kind of way that kills its enemy

C. a kind of poisonous liquid of some animals 

D. the gas which could cause death

43. Why does a victim get into shock after being injected?

A. He or it is too afraid to move about.

B. His or its organs can’t get enough blood.

C. His or its body was hurt and shuts down.

D. He or it is bitten and loses much blood.

44. Komodo dragons can’t easily hurt us because ______.

A. they are afraid of human beings

B. the venom in them is not so powerful

C. our blood can make them close to us

D. they only inhabit a few islands in Indonesia

题型:单项选择题

一矩形线圈在匀强磁场中转动,产生的感应电动势e=220

2
sin100πt(V),则(  )

A.交流电的频率是100πHz

B.t=0时线圈位于中性面

C.交流电的周期是0.02s

D.t=0.05s时,e有最大值

题型:单项选择题

用皮带传动的机器,当皮带使用时间长而发生打滑现象时,采用下列方法来增大摩擦,其中不可行的方法是 [ ]

A、张紧皮带

B、加润滑油

C、打皮带蜡

D、更换新皮带

题型:单项选择题

给水泵的轴端密封装置是哪种类型?

题型:单项选择题

审查汇票保证人是否作出保证时,必须把握汇票记载的事项有()

A.是否记载“保证”字样

B.是否有被保证人名称

C.是否有保证日期

D.保证人是否签章

更多题库