It took us about two hours _________ _________ the top of the mountain. 我们花费了大约两个小时的时间到达山顶。
答案: to reach 【详解】 It took sb. some time to do sth. 做某事花费某人多少时间,此处缺少动词不定式,第一空填 to ; “ 到达 ” 可译为 get to/arrive in/arrive at/reach ,根据空格可知第二空填 reach 。故填 to reach 。