问题 单项选择题 A2型题

某鸡场4月龄鸡群,出现精神沉郁,翅膀下垂,羽毛松乱,消瘦。剖检可见肝脏、心脏和脾脏等器官出现灰白色肿块,质地坚硬,法氏囊萎缩。你认为不宜采用以下哪种方法做进一步确诊()

A.用IFA检测肝组织中MDV

B.用ELISA方法检测MDV抗体

C.用PCR方法检测病鸡羽髓MDV

D.用免疫组化法检测MD肿瘤标记

E.琼脂扩散试验检测病鸡羽髓MDV

答案

参考答案:B

解析:禽的传染病,马立克氏病(MD)内脏型:多呈急性暴发,该型的特征是一种或多种内脏器官及性腺发肿瘤。病鸡起初无明显症状,呈进行性消瘦,冠髯萎缩、颜色变淡、无光泽,羽毛脏乱,后期精神委顿,极度消瘦,最后衰竭死亡。病理变化:内脏器官最常被侵害的卵巢,其次为肾、脾、肝、心、肺、胰、肠系膜和肠道。肌肉和皮肤也可受害。在上述器官和组织中可见大小不等的肿瘤块,灰白色,质地坚硬而致密,有时肿瘤呈弥漫性,使整个器官变得很大。法氏囊的病变通常为萎缩,有时因滤泡间肿瘤细胞分布呈弥漫性增厚,但不会形成结节状肿瘤。接种疫苗的鸡虽能得到保护不发生MD,但仍能感染MDV强毒。因此,是否感染MDV不能作为诊断MD的标准,必须根据疾病特异的流行病学、临诊症状、病理学和肿瘤标记作出诊断,而血清学和病毒学方法主要用于鸡群感染情况的监测。【考试科目】《兽医传染病学》

阅读理解

At three a.m., Jack Mills was sitting at the controls of the mail train. The train was made up of 13 cars. At the end of the train, 71 mailmen sat sorting the mail. Inside the second car, there were only five mailmen and 128 bags full of five-pound notes. This train had run more than 100 years without being robbed(抢劫). At three minutes past three, Mills and his helper, David Whitby, saw a yellow warning light. They slowed the train, and then stopped. Whitby went to the telephone beside the track. It was out of order. Then he saw a man moving between the second and the third cars. Before Whitby could give a warning, he was knocked down by two men. Mills’ cars with all the mailmen had been disconnected by the robbers. At the bridge, the bags of money were unloaded from the train and thrown into waiting trucks. One of the robbers who obviously knew the schedules(时刻表) of all the trains kept looking at his watch. At 3:45 he said, “That will have to be enough.” The robbers drove away with more than 2,500,000 pounds.

41. The robbery took place______.

A. before 3:03                                                         B. in the early morning   

C. after three o’clock in the afternoon             D. after 3:45

42. The robbers_____ before the train stopped.

A. were all in the train                                          B. forced Mills to stop the train

C. were waiting for the train to stop                D. ordered Mills to go on driving

43. Why didn’t the other mailmen help the mailmen in the second car when the robbery happened?

A. Because they were busy sorting the mail.

B. Because they didn’t want to help the mailmen in the second car.

C. Because the last eleven cars were separated from the front cars.

D. Because they knew nothing about the robbery.

44. One of the robbers kept looking at his watch because________.

A. he wanted to know the exact time               B. he enjoyed looking at his watch

C. he didn’t know when another train would come

D. they had to leave before another train came

45. Which of the following is NOT true?

A. The train was out of order.         

B. The telephone was put out of order by the robbers

C. Whitby had an assistant driver.          

D. The robbers carried the money away by truck.

问答题 简答题