V-ed和having been v-ed的区别
问题描述：
V-ed和having been v-ed的区别
when completed ,the museum will be open to the public next year.
中的completed能用having been compled 互换吗?
它们都是表示过去被动吧.
答
completed is correct.
having been done means a thing keep happening from a moment in the past to now.