(91~93题共用题干) 男性,55岁。1年来发作性心前区疼痛,每于劳累或生气时发作,向咽部放射,持续数分钟,可自行缓解。2周来发作较前频繁,未认真治疗。2小时前开始疼痛剧烈,部位同前,向左下颌放射,不能缓解。伴憋闷、出汗来急诊。 如x线片示右胫骨上段有死腔及大块死骨,包壳形成完整,治疗是
A. 病灶清除肌瓣填塞术
B. 死骨摘除窦道切除术
C. 窦道分泌物作细菌培养及敏感试验,选用合适的抗生素
D. 右下肢长腿石膏固定,继续换药
Directions: There are five reading Passages in this part. Each passage is followed by five questions. For each question there are four suggested answers marked A, B, C and D. Choose one best answer and blacken the corresponding letter on ANSWER SHEET I.Passage OneSince the early 1980s, scientists have revealed some 40 human genes involved in cancer. These genes are essential for normal growth, but can be subverted to cause a tumor.Dr. Jorge Yunis of the University of Minnesota Medical School in Minneapolis has found that 70 percent of oncogenes, or cancer-causing genes, are located near inherited weak points on chromosomes(染色体). Varying from individual to individual, vulnerable to chemical carcinogens(致癌剂) ,X rays and other cancer-inducing agents."If a chromosome snaps apart in the immediate vicinity of an oncogene," says Yunis, "normal genetic control mechanisms could break down and the stage would be set for the formation of cancer." Younis hag shown that such a sequence occurs at the beginning of numerous leukemias (白血病), lymphomas (淋巴瘤) and some tumors of the lung, colon (结肠) and breast.Yunis and Other investigators have found that petroleum-based products--notably pesticides and insecticides--damage specific sites on at least two of the 23 pairs of human chromosomes that carry genetic information. Similarly, tobacco smoke tends to attack a part of another chromosome. Under what conditions will the formation of cancer begin()
A. When a chromosome breaks apart neat an oncogene and its control functions fail.
B. When people drink too much and are easy to get tired.
C. When people smoke too much and are difficult to get to sleep.
D. When people eat too much petroleum-based products.