英语翻译有几个英语问题,1、翻译：At how he did it-without bitterness or comp

英语翻译
有几个英语问题,
1、翻译：At how he did it-without bitterness or complaint.
2、翻译：He is home on leave from the Navy now.
为什么用on?
后面这些是完形填空
3、They regretted missing their chance to have been of service.
为什么用of,不用for和to?
4、One good deed can awaken us to new and greater opportunities.
为什么用awaken,不用wake和find?