不是说 alive 不可以用于名词前作定语的吗？但下面这句呢？为何可以？
The similarities between Mars and Earth were enough to keep alive hopes of some form of Martian life. 火星和地球之间的很多相似处足以叫人们对火星上存在某种生物抱以期望。
The similarities between Mars and Earth were enough to keep alive hopes of some form of Martian life.
1. 不定式的结构是：keep + 宾语 + 形容词（宾补）
2. 因宾语hopes of some form of Martian life 太长，为了照顾句子的匀称，把形容词alive 提前了。
3. keep hopes of some form of Martian life alive的意思是：使得......期望充满着的。alive不是“活着的”，而是表示“期望满满的，信心满满的”之意。
这种现象也叫作“词汇分隔”或“成分分隔”现象。这是谓语和宾语被宾补分隔。又如：
The discovery has made possible new techniques for brain surgery.
Finally, I dashed down the stairs, pushed open the front door.
He was told to speak briefly; accordingly he cut short his remarks.
