英语填空题 The old man grasped my hand warmly and shook it, saying,"Congratualations,You've won."

问题描述:

英语填空题 The old man grasped my hand warmly and shook it, saying,"Congratualations,You've won."
这里的grasp为什么要用过去式的呢,从哪里看得出是在过去说的啊

shook也是shake的过去时啊