v.轻声低语,咕哝地抱怨( mutter的现在分词 );
n.(私下的)抱怨,牢骚,喃喃自语;
例句:
William went away muttering to himself.
威廉喃喃自语着走开了。
What is she muttering about?
她在咕哝些什么?
He was muttering away to himself.
他不停地喃喃自语.