咕嘟

例句：

1. 1. The dogwas making a low, rumbling soundas it drank from the bowl.
   狗在喝水时发出了低沉、缓慢的声音。
2. 2. The babywas murmuring softly to himself in hissleep.
   宝宝在睡觉时低声自语。
3. 3. Theold man was muttering under hisbreath about the weather.
   老人低声嘀咕着对天气的评价。