婴儿腹泻的病因，下列哪项是错误的（）。
A.肠道内感染
B.喂养不当
C.消化系统发育不成熟
D.血液中IgG偏低
E.肠道外感染
参考答案：D
解析：小儿腹泻的病因包括：消化系统发育不完善，胃酸较少、消化酶分泌较少、活性较低，对食物变化的耐受性较差；生长发育快，所需营养物质相对较多，消化道负担重，容易发生功能紊乱；机体防御功能较差，胃酸低、血中免疫球蛋白和胃肠道SlgA均较低；新生儿正常肠道菌群未建立；人工喂养，缺乏母乳中含有的体液因子、巨噬细胞等物质，抗肠道感染能力差，且食物与食具易污染。本题IgG偏低是发病机制，不属于病因范畴。A、B、C、E均属腹泻病因。本题选D。避错：部分考生会选C。消化系统发育不成熟，认为这是先天疾病，不会引起腹泻，本题A、B、C、E均是婴儿腹泻的病因，D．血液中IgG偏低错误，血中免疫球蛋白和胃肠道SlgA较低是导致小儿腹泻的病因，因此，本题选择D。
| The field of medicine has always attracted its share of quacks and charlatans — disrepu-table women and men with little or no medical knowledge who promise quick cures at cheap prices. The reasons why quackery thrives even in modem times are easy to find. To begin with, pain seems to be a chronic human condition. A person whose body or mind "hurts" will often pay any amount of money for the promise of relief. Second, even the best medical treatment cannot cure all the ills that beset men and women. People who mistrust or dislike the truths that their physicians tell them often turn to more sympathetic ears. Many people lack the training necessary to evaluate medical claims. Given the choice between (a) a reputable physician who says a cure for cancer will be long, expensive and may not work at all, and (b) a salesperson who says that several bottles of a secret formula "snake oil" will cure not only cancer but tuberculosis as well, some individuals will opt for "snake oil". Many "snake oil" remedies are highly laced with alcohol or narcotic drugs. Anyone who drinks them may get so drunk or stoned that they drown their pains in the rising tide of pleasant intoxication. Little wonder that "snake oil" is a popular cure-all for minor aches and hurts! But let there be no misunderstandings. A very few "home remedies" actually work. However, most remedies sold by quacks are not only useless, but often can be harmful as well. |
"Snake oil" is a popular cure-all for minor aches and hurts because it has______.
A．actually worked
B．some fruit stones
C．been misunderstood
D．alcohol or narcotic drugs