关于英语主动变被动的小问题.They have to built many houses since last year.变为被动后：Houses have to been built since last year.这么变对么?be 为什么要改为 been?没有be 变成 been
问题描述：
关于英语主动变被动的小问题.
They have to built many houses since last year.
变为被动后：
Houses have to been built since last year.
这么变对么?
be 为什么要改为 been?
没有be 变成 been
答
原句就错了:They have to build many houses since last year.
Many houses have to be built (by them)since last year.
答
原句MS就有问题...时态好像不对
变被动不对 要用be 不能用been
原句估计应该是 They have built many houses since last year.
变被动后 Many houses have been built since last year.