"Class is about to start" 是表示 "马上要上课了" 的常用英文表达方式。
来源：这是一种常用的日常用语，常用于学校和其他教育场合。
例句：
"Hurry up, class is about to start." (快点，马上要上课了。)
"I have to go, class is about to start." (我得走了，马上要上课了。)
"Can you finish your work quickly? Class is about to start." (你能快点完成你的工作吗？马上要上课了。)