表面声波屏需要经常清洁吗？

Does the sound wave screen need to be often cleaned?

youdao

这时，雪的表面就会反射声波。

Then, the snow's surface will help to send back sound waves.

youdao

这时，雪的表面就会反射声波。

Then, the snow's surface will help to send back sound waves.

youdao