leave for 是出发至某处
leave to是留某事给…处理
leavev.离开(某人或某处);离开居住地点(或群体、工作单位等);遗弃;丢弃
Her personal view is that they should leave for Shanghai in October.
她个人认为他们应该10月份动身去上海。
It is with regret that I have to leave for Shanghai.
很遗憾，我不得不启程前往上海。
You may have our leave to visit the workshop.
我们同意你去参观这个车间。
