She told us to stay away from the dog because it （would） cost much money to buy food for it.她告诉我们远离那条狗,因为它会让我们破费太多给它买狗食.will要填过去式would,因为主句的told说明时态为一般过去...这是个宾语从句吗不是。because引导的是原因状语从句。told后面的是不定式短语。