大学英语：After hospitals buy the expensive equipment that is necessary

　　8. After hospitals buy the expensive equipment that is necessary for modern heart surgery， they must try to recover the money they have spent.

　　本句中的equipment 是不可数名词，不能在后面加s.equipment后面的谓语动词也用单数形式。

　　1) The modern equipment enables them to double their production.(现代化的设备使他们能把产量翻倍。)

　　2) They decided to buy some new equipment.(他们决定购买新设备。)

　　3) Advanced equipment is necessary for this work.(干这个活需要先进的设备。)

　　还请注意，recover 在本句中的意思是get back(回收)。

　　1) We must try to recover lost time.(我们必须设法弥补失去的时间。)

　　2) They recovered increased costs through higher prices.(他们通过提高价格来补偿上涨的成本。)

　　9. In the past， people tended to think that it was sufficient for good health to have a good doctor who could be relied on to know exactly what to do when they became ill.

　　That引导的是一个宾语从句。在这个宾语从句中，it 做形式主语，真正的主语是to have a good doctor. Who引导的是一个定语从句，修饰doctor.what to do 做know的宾语。这句话的意思是，“过去，人们往往认为有个可以信赖的好医生就足以使他们有好身体，因为这个医生知道在他们生病时究竟该做什么。”