練習：2009年衛(wèi)生類ab級概括大意與完成句子
cancer癌癥
1 cancer癌癥 is a group of一組一群 many related相關(guān)的 diseases疾病 that begin in 開始，始于cells細胞, the body's basic基本的 building blocks.生命控制中心 the body is made up of many types of cells. 2normally,通常地 cells grow生長 and divide 分裂to produce產(chǎn)生 more cells as當---的時候 they are needed to keep the body healthy. 保持身體健康sometimes, this orderly process goes wrong. 3new cells form形成 when the body does not need them, and old cells do not die when they should. the extra cells form a mass of tissue called a growth or tumor. benign (良性的) tumors are not cancer. they can often be removed and, in most cases, they do not come back. malignant (惡性的) tumors are cancer. cells in malignant tumors are abnormal and divide without control or order.
4 scientists have learned that cancer is caused by 被---引起changes 改變變化in genes基因 that normally control 控制the growth生長 and death 死亡of cells. 5 certain 某種lifestyle生活方式 and environmental 環(huán)境factors因素can change some normal正常的 genes into 把---變成----genes that allow允許 the growth of cancer. 6 many gene changes that lead to 導致cancer are the result of tobacco 煙草use使用, diet飲食, exposure暴露 to ultraviolet [,ʌltrə'vaiələt]紫外線的radiation輻射 from the sun, or exposure to carcinogens [kɑ:'sinədʒən]（致癌物） in the workplace or in the environment.外界 some gene alterations are inherited.
cancer treatment can include surgery, radiation therapy, chemotherapy (化療), hormone therapy, and biological therapy. the doctor may use one method or a combination of methods, depending on the type and location of the cancer, whether the disease has spread, the patient's age and general health, and other factors. 7 because treatment 治療for cancer can also damage毀壞 healthy健康的 cells and tissues組織, it often causes side effects.副作用 patients and doctors generally discuss the treatment options, weighing the likely benefits of killing cancer cells and the risks of possible side effects.
having cancer does not always mean having pain. 8 whether a patient has pain may depend on 取決于the type類型 of cancer, the extent 程度of the disease, and the patient's tolerance忍受 for pain. 9most pain occurs when the cancer grows and presses壓迫 against bones骨頭, organs器官, or nerves神經(jīng). pain may also be a side effect of treatment. however, pain can generally be relieved or reduced with prescription medicines or over-the-counter drugs recommended by the doctor.