目前，我国证券市场推出的权证均为（）。 A.债券类权证 B.股本权证 C.股权类权证

骨折诊断要点包括（）

A.骨折的部位

B.骨痂形成

C.有无骨化性肌炎

D.有无畸形愈合

E.有无延迟愈合

灰阶超声波的回声来源是

A．超声波的全反射

B．超声波的背向散射及反射

C．超声波的衍射和折射

D．超声波的多普勒效应

E．超声波的绕射

剥掉树木主干的一圈树皮，树会慢慢死亡．这是因为切断了有机物向下运输的______，根得不到有机营养而死亡．

在软件生存中， (49) 阶段所占的工作量最大，约70%。

结构化分析方法产生的系统说明书由一套分层的 (50) 图、一本数据字典、一组说明以及补充材料组成。

软件的 (51) 一般由两次故障时间和故障平均恢复时间来度量。

采用 (52) 编写程序，可提高程序的可移植性。

仅根据规格说明书描述的程序功能来设计测试用例的方法称为 (53) 。

52（）

A．机器语言

B．宏指令

C．汇编语言

D．高级语言

Did you get a flu shot this year？For the first time，the Centers for Disease Control and Prevention in the US is recommending that all children aged from 6 months to 18 years receive the flu vaccine.

Vaccines battle diseases caused by bacteria and viruses.A weakened form of the germ (病菌) is introduced into the body.The body makes special substances called antibodies (抗体) to fight the germs.If the actual germs were to attack，the antibodies would fight.Because there are many kinds of flu viruses，scientists must create a new vaccine formula (处方) each year.Researchers must make a prediction.

It is like forecasting the weather.Sometimes they are right on，and sometimes they are off.But even when the vaccine does not closely match circulating flu types，it can make the illness less serious.

“The flu vaccine is not as effective as the polio (小儿麻痹症) vaccine or the measles vaccine，” says Dr.William Schaffner of Vanderbilt University School of Medicine.“It’s not a great vaccine，but it is in fact quite a good vaccine.”

But a flu vaccine doesn’t work for everyone.There are certain people who should be careful about taking it，because the vaccine is produced in eggs.Those who are allergic (过敏的) to eggs should not take it.If you have a fever，you should wait until you recover.

Some people are afraid that they might get the flu from the flu shot.Scientists say that it is not possible，because the viruses in the flu shot are inactivated.But some minor side effects such as low­grade fever and body ache could occur.If they do，they begin soon after the shot and usually last only one to two days.

Did you know？Smallpox was the first disease people tried to prevent by putting a virus into a healthy person.In 1796，English scientist Edward Jenner placed some infected material under a boy’s skin.

小题1:The underlined word “vaccine” (in Para.1) refers to________.

A．virus used for fighting against disease

B．antibody to fight the germs

C．formula to fight against disease

D．germ to be injected into the body小题2:By saying “It’s not a great vaccine，but it is in fact quite a good vaccine.” (in Para.4)，William Schaffner means the flu vaccine________.

A．is as effective as the polio and the measles vaccines

B．is worse，compared with the polio and the measles vaccines

C．does help to make illness less serious

D．is quite good because it works for everyone小题3:We can infer from the passage that________.

A．those who are not allergic to eggs can take the flu vaccine

B．not all the flu vaccines are effective for everyone

C．you should go to a doctor if you have a fever after taking the flu vaccine

D．it is possible that some people might get the flu from the flu shot小题4:When people take the flu vaccine，________.

A．they’ll be allergic to eggs

B．their bodies will ache for 5 days

C．they probably have a low fever

D．they won’t catch a flu ever after