We need to reflect on what has been achieved over the past ten years. To understand what is happening now.
【正确答案】：We need to reflect on what has been achieved over the past ten years to understand what is happening now.
【题目解析】：不定式不能独立成句，所以我们把两个部分连接起来成为一句话，其中不定式to understand用来表示目的。
