Unlike chemical pesticides, sound waves leave no toxic residue.

与化学农药不同，声波不会留下有毒残留物。

But when it's all over, and the insects are dead, there are no toxic residues to endanger humans or pets, and no funny smells.

但是当一切都结束，昆虫都死了，就没有危害人类或宠物的有毒残留物，也没有奇怪的气味了。