如图所示，物块的长度是_____cm．

关于双侧椎动脉MRA，正确的描述是（）

A.多选相位对比法

B.可替代椎动脉造影

C.一侧变细可诊断异常

D.与血管造影意义相同

E.颈椎退变时，可扭曲、粗细不均

阅读理解.

     It feels like every time my mother and I start to have a conversation,it turns into an

argument.We talk about something as simple as dinner plans and suddenly,my mother

will push the conversation into World War ?.She'll talk about my lack of a bright future

because I don't plan to be a doctor.And much to her disappointment,I don't want to do

any job related to science,either.In fact,when I was pushed to say that I planned to major

(主修) in English and communications,she nearly had a heart attack.

     "Why can't you be like my coworker's son?" she bemoans all the time.Her coworker's

son received a fouryear scholarship and is now earning 70,000 dollars a year as an engineer.

I don't know what to answer except that I simply can't be like Mr Perfect as I've called the

unnamed coworker's son.I can't be like him.I'm the type of person who loves to help out in

the community,write until the sun goes down,and most of all,wants to achieve a career

because I love it,not because of fame (名声) or salary.

     I understand why my mother is worried about my future major.I've seen my mother

struggle to raise me on her small salary and work long hours.She leaves the house around

6﹕30 am and usually comes home around 5 pm or even 6 pm.However,I want her to

know that by becoming a doctor,it doesn't mean I'll be successful.I'd rather follow my

dreams and create my own future.

1. Which of the following topics do the writer and his mother often talk about?

A．The writer's studies.

B．The writer's future job.

C．Dinner plans.

D．Wars around the world.

2．We can infer from Paragraph 1 that the writer's mother________.

A．doesn't want the writer to major in English

B．doesn't think the writer should be a doctor

C．gets along very well with the writer

D．doesn't think working in the science field is a good idea

3．The underlined word "bemoans" in Paragraph 2 most probably means "________"．

A．agrees

B．shouts

C．complains

D．smiles

4．Which of the following statements is probably TRUE about the writer?______.

A．He wants to be like his mother's coworker's son.

B．He wants to find a job in his community in the future.

C．He doesn't think his mother's coworker's son is perfect.

D．He wants to do something he really likes in the future.

5．We can know from the last paragraph that________.

A．the writer doesn't know what his future will be like

B．the writer's mother works very hard for the family

C．the writer doesn't think being a doctor is a good job

D．the writer sometimes thinks his mother's advice is very good

灵敏度数值越大，则仪表越（）。

A.不灵敏

B.灵敏

C.不一定灵敏

D.不变

某研究者，为了验证氯霉素对伤寒的疗效，在408例伤寒病人中进行对照试验，其中251例用氯霉素治疗，其余157例不用。结果使用组251人中死亡20人，死亡率7．07％，未用组157人中死亡36人，病死率22．8％，已有结论被亲自证实。

在临床医学研究中，对受试者应该做到的是（）

A.以科学利益放在第一位，病人利益放在第二位

B.危重病人和病情发展变化快的患者不应使用安慰剂

C.在医学研究中，即使病人病情恶化也不可以中断实验

D.为了更好的获得实验数据，可以对病人说谎，可以不解答病人的疑问

E.在医学研究中，不必一味坚持知情同意

化学成分遇水易酶解的药材为（）

A.黄柏

B.黄芩

C.地黄

D.黄芪