It's __ eight o'clock,I must go.空格应选哪个介词?为什么?about ,at ,for 等
问题描述：
It's __ eight o'clock,I must go.空格应选哪个介词?为什么?about ,at ,for 等
答案是about哦,可语法上怎么解释不选at呢?
答
about 大约,差不多 的意思
现在差不多8点了,我得走了