问题
单项选择题
某70岁女患者因尿路感染于5天前开始服用氨苄青霉素。现出现腹泻。取便标本,培养出大量革兰阳性葡萄球菌。试问腹泻发生机制是
A.菌群失调
B.肠毒素使腺苷环化酶活性增加
C.细菌侵袭肠黏膜所致
D.内毒素作用于肠黏膜
E.肠蠕动加快
答案
参考答案:A
某70岁女患者因尿路感染于5天前开始服用氨苄青霉素。现出现腹泻。取便标本,培养出大量革兰阳性葡萄球菌。试问腹泻发生机制是
A.菌群失调
B.肠毒素使腺苷环化酶活性增加
C.细菌侵袭肠黏膜所致
D.内毒素作用于肠黏膜
E.肠蠕动加快
参考答案:A
完形填空。 |
We know that trees are useful in our everyday life. They 1 us many things, such as wood, rubber, medicine and many other things. They can 2 tell us a lot about our climate (气候). If you 3 a tree, you can see that it has many rings (年轮). Most trees get a new ring 4 year. Because of this reason, we know 5 a tree is. A tree over a hundred years old means that it has more than a hundred 6 . When the climate is dry or very cold, the trees do not grow very much and their rings are usually 7 . When it is wet and warm, the rings are much thicker. If the rings are suddenly (突然地) very thin or very thick, this means that the 8 changed suddenly. If we look at the rings on this tree, we can learn 9 the climate for a hundred years. And we can see 10 our climate is changing today. |
( )1. A. tell ( )2. A. not ( )3. A. cut down ( )4. A. many ( )5. A. how big ( )6. A. trees ( )7. A. big ( )8. A. climate ( )9. A. about ( )10. A. when | B. ask B. too B. climb up B. every B. how long B. leaves B. thin B. trees B. to B. where | C. offer C. to C. walk past C. the first C. how old C. people C. large C. things C. with C. how | D. get D. also D. look at D. from D. how much D. rings D. thick D. animal D. in D. while |