The sign on the birds' cage means we should keep quiet 否定句

问题描述:

The sign on the birds' cage means we should keep quiet 否定句

有2种否定方式:
一是否定主句
The sign on the birds' cage doesn’tmean we should keep quiet
二是否定从句:
The sign on the birds' cage means we should not keep quiet
第一种更符合要求