题目内容：

关于被动语态的问题
1.The ancient Egyptians are supposed to have sent rockets to the moon a long time ago.
为什么要用have?
2.Everything taken into consideration,the plan Xiao Wang put forward seems to be more workable.
前半句中的taken是做什么成分?为什么不用be动词?
为什么第一题的be动词不是用过去时？