英语问题（入门）all possible means have been tried to save the boy.为何用have been不用 has been 、have、 was
2019-06-15
英语问题（入门）
all possible means have been tried to save the boy.为何用have been不用 has been 、have、 was
优质解答
all possible means应该表示复数
要修饰 tried ,而且是个定语从句,所以要用been
all possible means应该表示复数
要修饰 tried ,而且是个定语从句,所以要用been