(know)______that they were going traveling ,the students began to make preparations.
问题描述：
(know)______that they were going traveling ,the students began to make preparations.
答案是knowing填having known不行吗
答
用动名词 可以表达一种特殊的意思 一.就.
这里 学生们一听说要去旅行,就开始做准备,
以此表现学生一听说马上开始激动作准备
用 having known知道以后,这里以后可能是很久以后,没有前者的表达效果好 ,准确