第2个回答 2013-07-29
being done 正在被…… 例如:there is a new shopping mall being built next to the metro now.
done 已经/被…… 例如:Noticed by the police, the thief immediately ran away.(表示被动)
once bitten, twice shy. 一朝被蛇咬,十年怕井绳。(被动完成)
having been done 早已经被…… 在不强调动作先后的情况下,常常用done代替。
例如:having been threatened twice, the young lady called the police.
threatened twice, the young lady called the police.