1．The__________ (possible)that there is life on other planets in the universe has always inspired scientists to explore the outer space.
【答案】possibility
【解析】考查名词词义辨析及语境理解。句意：宇宙中其它星球上存在生命这种可能性总是激励科学家们去探索外部空间。故填possibility。
2. Try to understand what’s actually happening instead of acting on the _______ （assume）you’ve made.
【答案】assumption
【解析】考查名词词义辨析及语境理解。句意：试着去理解实际发生的事情，而不是按照你所做的假设行事。 故选assumption 。
3. In 1863 the first underground passenger railway in the world opened in London. It ran for just under seven kilometers and allowed people to avoid terrible (crowd) on the roads above as they travelled to and from work.
【答案】crowds
【解析】考查名词。crowd前没有冠词、指示代词和形容词性人称代词，故用复数形式。
