Did you swim across the river Have you swam across the river?这两句话有什么区别
问题描述：
Did you swim across the river Have you swam across the river?这两句话有什么区别
答
Did you swim across the river -----强调“当时”是否游过河了
Have you swum across the river?-----强调到“目前为止”是否有过游过河这样的经历