have an opportunity to do与doing的区别？

Last month i had an opportunity ____ at the local hospital.
为什么上空填的是volunteering,而不用to volunteer

就是to volunteer，不是volunteering

只有have an opportunity of doing 做某事的机会 eg: this gave him an opportunity of collecting his thoughts. 这给了他一个机会镇定下来。 have an opportunity to do 有机会做某事 if you owe someone an apology or have an opportunity to soothe things over, then do it. 如果你欠某人一个抱歉或是有机会让事情好转，那么就去做。 希望对你有帮助哦~