老师告诉他的学生们光的速度比声音快用英语怎么说

The teacher tells their student to say glossy speed is quicker than sound

The teacher told his students that light travels faster than sound .
因为是陈述真理客观事实，所以用一般现在时。

The teacher tells his students that the speed of light faster than the sound .

the teachter told her students that THE LIGHT IS FASTER THAN VOICE.