| 患者右下第一前磨牙及右上第一，第二磨牙残根，既往曾有风湿性心脏病史10余年，现存在二尖瓣狭窄，心功能Ⅰ级 |
对此患者施行牙拔除术时须慎重，否则容易引起的严重并发症是
A．颊间隙感染
B．颌下间隙感染
C．干槽症
D．败血症
E．亚急性细菌性心内膜炎
参考答案：E
解析：对此患者施行牙拔除术时须慎重，否则容易引起的严重并发症是亚急性细菌性心内膜炎。
| Some pioneering work that began as an attempt to discover ways to increase production efficiency led to the founding of the human relations movement in industry and to the development of motivational skills and tools for managers. In 1927 researchers were involved in determining the optimum amount of lighting, temperature, and humidity (with lighting being considered the most important) for the assembly of electronic components at Western Electric. The researchers found that lighting had no consistent effect on production. In fact, production sometimes increased when lighting was reduced to the level of ordinary moonlight! The important part of this experiment began when two Harvard researchers, Elton Mayo and Fritz Roethlisberger, were brought in to investigate these unexpected results further. They found that workers were responding not to the level of lighting but to the fact that they were being observed by the experimenters. This phenomenon came to be known as the Hawthorne effect since the experiments were conducted at the Western Electric Hawthorne Plant. This was the first documented and widely published evidence of the psychological effects on doing work, and it led to the first serious effort aimed at examining psychological and social factors in the workplace. Further experiments were continued for five years. Generally, the researchers concluded from their experiments that economic motivation (pay) was not the sole source of productivity and, in some cases, not even the most important source. Through interviews and test results, the researchers focused on the effects of work attitudes, supervision, and the peer group and other social forces, on productivity. Their findings laid the groundwork for modem motivation theory, and the study of human factors on the job, which continues to this day in such common practices as selection and training, establishing favorable work conditions, counseling, and personnel operations. The contributions of this experiment shifted the focus of human motivation from economics to a multifaceted approach including psychological and social forces. |
Why does the author say that the important part of this research began when two Harvard researchers were brought in
A．Until then the research had been poorly conducted.
B．They took a multifaceted approach.
C．The results of the original research did not make sense.
D．Harvard had a good reputation in conducting research.