新概念第三册语法问题

题目

新概念第三册语法问题
第五课当中的两句话：1.the article began:"hunderds of steps lead to the high wall which surrounds the president's palace."
2.he had been arrested while counting the 1,084 steps leading to the fifteen-foot wall which surrounded the president's palace.
后面一句中的“surround”和“lead”为什么是以这样的形式出现呢?前一句我还能理解,

答案

leading to.修饰steps
which surrounded...整个句子是过去时态啊,与第一句不同,第一句因为是在引用句中,引用句用的是现在时态