解析：句意：吃好锻炼好使你不感冒。keep sb.free of/from sth.意为"使......免除/摆脱......"。

　　8．From his __confused__ (confuse) look，we could see that professor hadn't expected that we could raise such __confusing__ (confuse) questions to him.

　　解析：句意：从这位教授的困惑的表情我们能看出，教授未料到我们能问如此令人困惑的问题。修饰人或人的look，expression等时都要用confused"感到迷惑的"；第二个空用confusing"令人迷惑的"，修饰物。

　　9．Creating a goal that focuses __on__ a well－specified input will likely be more effective than concentrating on the outcome.

　　解析：句意：设定一个目标，专注于细节的投入之上，这要比把注意力集中在结果上可能会更有效。focus on集中于。

　　10．__To free__ (free) ourselves from the physical and mental tensions，we each need deep thought and inner quietness.

　　解析：句意：为了舒缓身体和心理紧张，我们每一个人都需要深思和内心的安静。考查非谓语动词。空格处在句中作目的状语，故用不定式结构。

　　11．-Now that you didn't agree with him，why didn't you speak it out at the meeting？

　　-Well，now I regret not __doing__ (do) that.

　　解析：考查regret的用法。句意：--既然你不同意他的话，为什么不在会议上说出来呢？--噢，现在我后悔没那样做了。regret not后接动名词作宾语表示"后悔没做某事"。

　　12．The wide use of the Internet has already led to all kinds of information __being shared__ (share) all over the world.

　　解析：句意：网络的广泛使用使得各种信息在世界范围内分享。短语lead to中的to为介词，所以all kinds of information的宾语补足语应用动词－ing形式；share与information之间是被动关系。

　　13．With the pressure __building__ (build) up，she had to leave her work for a while because she couldn't stand it anymore.

解析：句意：随着压力的增加，她只好离开工作一段时间，因为她再也忍