to很显然是不定式, it comes time to的意思是,是做什么的时候了.
When it comes time to sit down and write the next book, you're deathly afraid that you're not up to the task
每当坐下来写下本书的时候,你总会非常担心自己不能胜任这项工作.
I won't have to alter my lifestyle much when it comes time to include marriage and children.
即使当结婚或有孩子时,我也不必过多的改变生活方式.
提问者对于答案的评价:谢谢