问题 单项选择题

患者,男,主诉右眼急性视力下降3天,眼底检查见视网膜广泛出血,视网膜静脉扩张迂曲,最先考虑的是()

A.视网膜中央静脉阻塞

B.视网膜中央动脉阻塞

C.原田病

D.球后视神经炎

E.视网膜脱离

答案

参考答案:A

解析:视网膜中央静脉阻塞视网膜出血的范围广,水肿明显,动脉变细,静脉充盈扩张伴视盘水肿、充血,可出现棉絮斑,题干提供的信息与此表现相似,故选A。

阅读理解

阅读理解。

                                                                  The Giraffe

      The giraffe is the tallest modem land animal. It can be over 5.5 metres tall. Its neck bone may be 1.9 metres

long. Yet the giraffe has only seven bones (骨) in its neck, the same number as in the human (人类). Even a

small bird has many more bones in its neck than in a tall giraffe. Each bone in a giraffe's neck is very long, while

the bones in a human neck are small. That makes the difference. A female (雌的) giraffe gives birth to one baby

at a time. The baby, called a calf, is about 1.9 metres tall at birth. By the age of eight it is full-grown. The giraffe

eats mostly leaves. Because it has a long neck, it can reach the leaves high up on the trees.

1. In this passage the underlined word "giraffe" means _______. [ ]

A. 鲸鱼

B. 长颈鹿

C. 大象

D. 恐龙

2. The number of the bones in a bird's neck is _______. [ ]

A. as big as in a human's neck

B. not so big as in a giraffe's neck

C. much more than in a human's neck

D. much smaller in a giraffe's neck

3. Which of the following is true according to this passage? [ ]

A. A giraffe has only seven bones.

B. Tile giraffe is the largest animal on land.

C. It takes eight years for a giraffe to grow up.

D. All the leaves on the trees will be eaten by giraffes if they live in that region.

4. The baby giraffe is about _______ at birth. [ ]

A. 5.5 metres long

B. 5.5 metres tall

C. 1.9 metres long

D. 1.9 metres tall

5. When a giraffe sees a tiger we can guess _______. [ ]

A. it will run away as fast as possible

B. it will run to eat the tiger

C. it will make the tiger bring it something to eat

D. it will bring some small animals for the tiger to eat

单项选择题