头颈部恶性肿瘤若先行术前放疗，放疗结束后再行手术的最佳时机是（）。
A.放疗结束后1周以内
B.放疗结束后1～2周
C.放疗结束后2～4周
D.放疗结束后4～6周
E.放疗结束后6～8周
参考答案：C
解析：放疗结束后2～4周是再行手术的最佳时机。如果间隔时间过短，放疗急性反应来过；间隔时间过长，会导致组织纤维化形成，这些均会导致手术难度增大和并发症增加。
There is an English saying: “Laughter is the best medicine.” Until recently, few people took the saying seriously. Now, however, doctors have begun to look into laughter and the _ _ it has on the human body. They have found that laughter really can _ _ people’s health. Tests were carried out to study the effects of laughter on the body. People watched funny films __ __ doctors checked their heart, blood pressure, breathing and muscles. It was found that laughter has similar effects to exercise. It decreases blood pressure, the heart beat and breathing; it also works several groups of muscles in the face, the stomach, and even the feet. If laughter the body, it must be beneficial. Other tests have shown that laughter appears to be able to reduce the effect of pain on the body. In one experiment doctors pain in groups of students who listened to different radio programs. The group that tolerated the pain for the time was the groups which listened to a funny program. The reason why laughter can reduce pain seems to be that it helps to produce a kind of chemicals in the brain which diminish( 减少 ) both stress and pain. As a of these discoveries, some doctors in the United States now hold laughter clinics, in which they help to improve their patients’ condition by __ them to laugh. They have found that even if their patients do not really feel like laughing, making them smile is enough to produce beneficial effects to those caused by laughter.
|