The distant rumbling of the guns mingles with our marching song.枪的深邃长声与我们行进歌混合.The crane made rumbling sound.吊车发出隆隆的响声.With a low-pitched rumbling noise, the propeller began to rotate.伴随着隆隆的低沉噪声，螺旋桨开始旋转起来。Lysenko gave a ...
We'll put together a proposal, including detailed costings, free of charge.我们将免费拟一份提案，其中包括详细的成本估算。The performers have all offered their services free of charge.演员们都愿意免费出演。The leaflet is available free of charge from...