adj.没有噪音的,寂静的,不出声的;无声;
例句:
His breath was perfectly noiseless.
他的呼吸是没有声息的.
Saving energy, noiseless operation, saving material.
节能, 无声运行, 节材.
High efficient, noiseless environment protection design.
高效率, 无噪音的环保设计.