难事

a piece of work; tickler

1. 学骑马是件难事。
   It's uphill work learning to ride.
2. 一天走20英里，他不以为是难事。
   He makes nothing of walking 20 miles in a day.
3. 空难事件中有些人大难不死被新闻界广泛报导。
   The miraculous survival of some people in the air crash was widely reported by the press.
4. 学骑自行车是件难事。
   It's uphill work learning to ride a bicycle.

事的英语翻译：