【正确答案】正确答案：Deep structure is formed by the XP rule in accordance with the head"s sub-categorization properties; it contains all the units and relationships that are necessary for interpreting the meaning of the sentence. Surface structure corresponds to the final syntactic form of the sentence which results from appropriate transformations; it is that of the sentence as it is pronounced or written.(3 points) Therefore, the sentence "Flying planes can be dangerous" can have two different deep structures; "If you fly planes you are engaged in a dangerous activity" or "Planes that are flying are dangerous. "(2 points)

【答案解析】解析：考查表层结构与深层结构及其应用。表层结构是声音或文字表现出来的可感知的结构；深层结构是潜在于人们意识中，不能直接感知的结构。无论是直接成分分析法还是树形图，都只能分析句子的表层结构。表层结构是实际上形成的句子各成分进行线性排列的结果，深层结构是短语或句子成分之间内在的语法关系，是不能直接从线性序列中看出来的。Flying planes can be dangerous(一表层，两深层)，可以解释为：开飞机会很危险或者飞行中的飞机会很危险。