原式=x2-4-12x+2•x+24-x=-(x+4)(x-4)x+2•x+2x-4=-(x+4)=-x-4.
The field of medicine has always attracted its share of quacks and charlatans — disreputable women and men with little or no medical knowledge who promise quick cures at cheap prices. The reasons why quackery thrives even in modern 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.
People who seek the advice of quacks and charlatans are those who________.
A.are poorly educated
B.are highly educated
C.dislike medical treatments
D.mistrust physicians’ truths
患儿男,13岁。1年前因右侧下后牙有冷热不适曾于外院治疗,近1个月来右下后牙区时有咬合不适,1日前出现咬合痛及自发痛。口内检查:右下第一磨牙远中面大面积充填物边缘探及腐质,远中部分缺损有大量食物嵌塞,龈 * * 略红肿。右下第二前磨牙面有畸形中央尖折断后的痕迹。第二恒磨牙部分萌出远中有盲袋,牙龈轻度红肿。
如果X线检查发现第二前磨牙根尖有阴影,且根尖孔未闭合应做哪些处理()
A.开髓
B.调
C.拔髓
D.冲洗并清理髓腔
E.疏通根管
F.ZOE封木榴油球