When a sand-carrying blast loses 20% of its velocity in front of and behind the net,the sand grains carried will fall one after another,terminating its risky travel.

• 当运载着沙尘的疾风在网前网后失掉20%25的速度时，所携带的沙粒便纷纷坠落，终止了它们危险的旅行。