That sign on the building means Danger.对on the building 如何进行提问提问:( )( )means "Danger"?

问题描述:

That sign on the building means Danger.对on the building 如何进行提问
提问:( )( )means "Danger"?

what on the building sign's mean?

Where is the sign (which) means Danger ?

Where is the sign which means Danger?用一个定语从句就可以.
Which sign means Danger?