The discordant hum of tourists below .

下面的游客发出不和谐的嗡嗡声。

Waves from the deep ocean don 't seem to make much hum at all .

而深海海浪似乎根本不会产生那么多的嗡嗡声。

The hum of the heater system was also mum .

平时嗡嗡作响的加热系统也保持了沉默。

She does not like poetry , but she likes to hum pop songs .

她并不喜欢诗歌，但是她喜欢哼流行歌曲。

Emerging economies such as china and brazil continue to hum .

中国和巴西等新兴经济体继续保持活跃。