When it cuts it leaves sticky ends or un-base paired single stranded regions on each end of the part its cut and that's just a property of many restriction enzymes; not all, some cut blunt,just right down the middle.

它切割后会留下两个粘性末端,或者未配对的单链部分,这是许多限制性内切酶的特性,但不是全部,有些限制性内切酶是从中间钝切的

耶鲁公开课 - 生物医学工程探索课程节选

Now another property of restriction enzymes is that they always cut the DNA in the same way.

限制性内切酶的另一个特性是,总是以同样的方式切割DNA

耶鲁公开课 - 生物医学工程探索课程节选