It(the suspicion of the pathient) contributes to the spiral of lawsuits and of “defensive medicine，” and thus it injures, in turn, the entire medical profession. 病人对医生的不信任使医疗诉讼案增多，造成医生避免风险的“防御性诊治”增多，而这些又进而有损于整个医疗事业。
13) Research into the dynamics of storms is directed toward improving the ability to predict these events to minimize damage and avoid loss of life.
［A］ and thus
［B］ so
［C］ however
［D］ because
40. unless 除非，如果不(引导条件状语从句)
Unless we are very careful, we can't do our work well. 如果不仔细的话，我们就不会把工作做好。
But he won't be much longer unless he has the medicines on that list. 但他不能活多久，除非有这单子上的药。
14) you return those books to the library immediately you will have to pay a fine.
［A］ Until
［B］ Unless
［C］ If
［D］ Provided
41. until 到……为止，最后(not…util，止到……才)(引导时间状语从句)
He pursued various theories for several days until I suggested we take the toy apart to see how it did work. 我劝说他好几天用其他理论(来解释它的工作原理)，最后我建议把那玩具拆开看一看它的工作原理。
Thereafter, he used the shaving cream every morning until the tube was empty.从那以后，他每天早晨用那剃须膏，直到用完。
It was not until the 18th century that man realised that the whole of the brain was involved in the workings of the mind.到了18世纪，人们才认识到人的整个大脑参与思维活动。
15) the 1500’s the first European explored the coast of California.
［A］ It was not until…then
［B］ It is not until…when
［C］ It is until…that
［D］ It was not until…that
42. when
① when可以状语从句表示“当……时候” When I speak he awayls whispers to others.