问题 单项选择题 A1型题

高度怀疑眼内磁性异物时,哪种检查应为禁忌()。

A.B超

B.UBM

C.MRI

D.X线照片

E.CT检查

答案

参考答案:C

解析:该题是基本概念题,备选答案是眼科常用的影像学检查。MRI是利用人体内的氢原子中的质子在强磁场内被相适应频率的射频脉冲激发,质子吸收能量产生共振。射频脉冲终止后质子恢复原态时释放出能量,即MRI信号,通过接收线圈接收并经计算机转换成MRI图像。凡球内、眶内及体内存留磁性金属异物及治疗性磁性物体者禁用,佩戴心脏起搏器者为绝对禁忌。

阅读理解

The adderis the only poisonous snake nativeto Britain. Adders have the most highly developed poison injecting mechanism of all snakes, but they are not aggressive animals. Adders will only use their poison as a last means of defence, usually if caught or trodden on. No one has died from adder bites in Britain for over 20 years. By far the most common smake in Britain is the adder. In Scotland, in fact, there are no other snakes at all. The adder is also the only British sanke with a poisonous bite. It can be found almost anywhere, but prefers sunny hillsides and rough open country, including high gournd. In Ireland there are no snakes at all.

Most people regard snake bites as a fatal misfortune, but not all bites are serious, and very few are fatal . Sometimes attempts at emergency treatment turn out to be more dangerous than the bite itself, with amateurs heroically, but mistakenly, trying do-it-yourself surgery and other unnecessary measures.

All snakes have small teeth, so it follows tha tall snakes can bite, but only te bite of the adder presents any danger. British snakes are shy animals and are far more frightened of you than you could possibly be of them. The adder will attack only if it feels threatened, as can happen if you take it by surprise and step on it accidentally, or if you try to catch it or pick it up, which it dislikes intensely. If it hears you coming, it will normally get out of the way as quickly as it can, but adders cannot move  very rapidly and may attack before moving if you are very close.

The effect of a bite varies considerably. It depends upon severa things, one of which is the boidy-wight of the person bitten. The bigger the person, the less harmful the bite is likely to be, which is why children suffer far more seriously from snake bites in Britain ,and thought these bites can make some pepe very ill, there are probably just as many cases of bites having little or no effect, as there are of serious illness.

小题1:What does the underlined phrase “ trodden on” probably mean?

A.Found out

B.Heard from

C.Stepped on.

D.Robbed of.小题2:Where are adders to be found?

A.In fertile fields in Scotland.

B.On wild land throughout Britain.

C.In many parts of Britain and Ireland.

D.Everywhere in Britian except Scotland小题3:What should you do if you are with someone who is bitten by an adder?

A.Catch the biting adder at onece.

B.Don’t worry about the bitten person.

C.Don’t try to treat the bite by yourself.

D.Operate on the person as soon as possible.小题4:What’s the best title of the passage?

A.Poisonous Snakes

B.Adders in Britain

C.Take Care oif Sake Bites

D.Protec Endangered Adders

填空题