问题 单项选择题

男性,18岁,阵发性心悸2年。每次突然发作,持续时间1小时左右,有时呕吐可以突然终止。心电图:QRS波正常,频率为210次/分,P波不明显,诊断可能性最大的为()

A.阵发性室上性心动过速

B.特发性室性心动过速

C.窦性心动过速

D.房性心动过速

E.心房扑动

答案

参考答案:A

解析:刺激迷走神经可以终止是阵发性室上性心动过速的一个特点。

填空题
单项选择题

Government officials reported three new cases of mad cow, bringing the total so far this year to 99. Last year, France recorded just 31 cases of the mad cow disease. The rising numbers are in part (1) a new testing program that focuses on cows that are most (2) . That program has (3) 39 cases. But still 60 new cases were identified in the usual way, (4) were found in 1999. Many scientists (5) that this year, five years after safety precautions were (6) , the number of cases would be (7) .

The rise in cases has (8) some scientists to question whether the disease can be transmitted in ways not yet understood. Scientists are still (9) the disease, first recognized in cows in 1986.

It appears that it is not caused by a bacteria, virus or fungus, but (10) infectious particles called prion, perhaps (11) a virus or other agent. The disease kills cells in the brain, (12) it spongy and full of holes.

France has taken more steps to (13) safety than most European countries, (14) refusing to take English beef (15) the European Union. But some scientists believe that France has not been (16) in imposing the ban on feed that (17) animal pans.

Some French officials hope that the sudden interest in mad cow disease will mean that French consumers will become educated about it, thereby recognizing that French beef is actually (18) controlled. Every cow is given a passport at birth, and extensive information about its parentage and (19) it was raised must be (20) to any slaughterhouse. When a diseased animal is found, the entire herd is destroyed.

12()

A.to leave

B.left

C.leaves

D.leaving