下面哪一种方法不能用来改善信噪比？（）A.将试验频率变为可使噪声减小的频率； B.增

阅读理解。

     Today Newtown is a very clean place. Many years ago, however, there were millions of rats (老鼠) in

 Newtown. They attacked the cats and dogs.

     Sometimes a great number of them knocked down a man or woman walking home at night. The rats

 were very large and they harmed many people.

     The Government ( 政府) ordered everybody to kill rats. Most people were very lazy, so they did not

 kill them. Then the Government promised to pay some money for each clead rat. That made people very

 happy. A Government officer put all the dead rats in a big pile. Sometimes a man brought hundreds in a

 day.

     After two weeks there were not many rats in the city, but people still brought rats to the Government

 officer.  The Government officer thought that people were stealing dead rats from the pile. He ordered his

  men to dig a deep hole and put the rats in it. Soon there were no more rats, and the Government did not 

 pay any more money.

1. The underlined phrase "a great number of" means

    A. a great deal      

    B. a good many of

    C. a great amount of

    D. a good much of

2. According to (根据) the passage, which of the following is TRUE?

    A. In Newtown, anyone who was riding home at night could be knocked down by rats.

    B. In Newtown, anyone who was at home at night could be knocked down by rats.

    C. In Newtown, anyone who was going home on foot at night could be knocked down by rats.

    D. No matter when the people in Newtown were walking home, they could be knocked down

        by rats.

3. Why were the people stealing the rats from the pile'?

    A. Because they thought the dead rats should be put in a deep hole.

    B. Because they thought it was a good way to get more money from the Government.

    C. Because they thought they were not lazy.

    D. Because they thought they were all poor and were forced to do so.

4.  Which of the following is TRUE?

    A. The officer ordered his men to dig a deep hole and put the dead rats in it just only to save money for 

          the Government.

    B. Soon the Government did not pay any more money, and there were no more rats.

    C. The officer wanted to teach the lazy people a lesson, so he ordered his men to put the dead rats in a

         deep hole.

    D. The officer and his men put the dead rats in a deep hole in order to prevent the dead rats from being

          stolen and get rid of all the rats in the city.

5. The best title for this passage should be_____.

    A. How Newtown Became a Very Clean Place

    B. How the People in Newtown Became Rich

    C. How to Kill Rats in a City

    D. Newtown-A Rat City

青年女性，有静脉注射麻醉药物史，高热10余天，偶有咳嗽，少量黄痰，院外静脉滴注青霉素、头孢等抗生素一周后体温下降到38℃，回家口服药物，两天前再次发热，体温39．7℃，一直持续发热，间断咳黄色浓痰，偶有痰中带血。急查血常规白细胞总数22．4×10⁹／L，中性粒细胞90％，胸片双肺多发片絮状阴影，并见多个空洞

如患者病情危重，首选的抗生素是（）.

A.二代头孢菌素

B.三代头孢菌素

C.抗霉菌药物

D.万古霉素

E.以上都不是

（）是指健康保险单在生效一段时期后，除非投保人或被保险人的误告是欺诈性的，否则保险人不能用保单中的实质性误告为由解除保险单或拒绝赔付。

A.续保条款

B.复效条款

C.不可抗辩条款

D.索赔条款

下列哪项不是老年人保健牙刷的特点（）。

A.刷头小

B.刷毛硬而有弹性

C.刷柄较扁而宽

D.刷毛软而有弹性

E.以上均是

男患，18岁，家住农村，家中畜养牛、羊、猪。近1个月反复出现抽搐，发作间期如常。头颅CT检查可见散在直径约0.5～1.0cm大小不等的圆形或类圆形低密度和高低混杂密度影及数个钙化灶。该患者最可能的诊断是（）

A.脑脓肿

B.脑肿瘤

C.脑膜炎

D.脑囊虫病

E.脑炎