have been doing 和 be being done 感觉是一个意思啊

have been doing 是现在完成进行时,表主动
be being done 是现在进行时的被动
意思两样可以举一个例子吗谢谢i have been skating for three hours 我已经溜冰三小时了（言下之意，我以前溜冰，现在还在溜冰，以后还会溜下去）因为是主动，所以主语是人the bridge is being built人们正在建桥 我再造一个你也许认为意思差不多的 peple have been building the bridge 人们还在建桥，（过去建，现在还在建，以后还会一直建）