用适当的动词和情态动词填空 They couldn't find any secrets.=They ( )not( )to find any secrets.

问题描述:

用适当的动词和情态动词填空 They couldn't find any secrets.=They ( )not( )to find any secrets.

were,able
这里be able to=can
祝你进步,有不会的可以再问我哦