根据句意及首字母或汉语提示，写出各句中所缺单词的正确形式。（每空一词，共10分）
小题1:As you go up a mountain, you have to overcome the earth’s g which pulls you down.
小题2:The m leaf has become the most important symbol of Canada since the national flag was introduced in 1965.
小题3:The little girl was t at the thought of being left alone at home and cried.
小题4:He went to the United States in the 1980s and s down there.
小题5:Don’t leave matches or cigarettes on the table w reach of little children.
小题6:How quickly a fuel burns depends on how well it is mixed with (氧气) or air.
小题7:The policemen were sent to find the black box because it showed why the plane had
(坠毁).
小题8:The idea (存在) only in the minds of us young people today.
小题9:This problem is only (稍微) difficult so I can work out.
小题10:They claimed that when they were (包围) by the gang they acted in self-defense.
小题1:gravity
小题2:maple
小题3:terrified
小题4: settled
小题5:within
小题6:oxygen
小题7:crashed
小题8:exists
小题9:slightly
小题10: surrounded
题目分析：
小题1: gravity 名词地球引力gravity，该词的使用范围不广，通常和名词earth连用，在上下文中很容易就可以判断出具体用法。
小题2: maple 根据下文的symbol of Canada可知是指加拿大的枫叶，maple leaf枫叶。
小题3: terrified 形容词感到害怕的terrified。是由动词terrify转换而成。
小题4:settled 动词短语定居settle down。注意一词多义现象，settle还可以表示姐居然。
小题5:within 固定搭配within the reach of在…的范围之内。
小题6: oxygen 名词氧气oxygen,该词属于专有名词，根据上下文很容易就可以判断。
小题7: crashed 动词坠毁crash,根据句意说明使用过去完成时，故使用过去分词的形式。
小题8: exists 动词存在exist因为后面的时间状语是today，故使用一般现在时。
小题9:slightly 副词稍微slightly做状语修饰形容词difficult。
小题10:surrounded 动词包围surround，本句使用被动语态的形式，故使用过去分词的形式。
点评：本题重在考查基础知识、基本词汇量的积累，对于这类题只有平时勤积累、多进行记忆背诵，对自己严格要求，考试时才能下笔如有神。