The plan is heard ____so well that we.

问题描述:

The plan is heard ____so well that we.
The plan is heard designed so well that we don't hane to make any changes
不是有be heard to dosth的吗为什么还要用design的过去式

designed so well (被)设计的如此之好
这是过去分词短语,做heard的宾语;实际上它是动词不定式的省略,原不等式应为“to be designed so well”,这里把"to be"省略了.
由于应是“The plan is heard to be designed so well” ,所以符合你所说的“be heard to do sth” 的习惯用法