cooing/kuː/动词(鸽子等)咕咕地叫The baby lay in his cot, cooing and gurgling.婴儿躺在自己的小床上,咿咿呀呀,咯咯笑着。名词首席运营官,营运长(chief operating office 的缩写)Most recently, he was COO of IFS Engineering.就在前不久,他还是IFS 工程公司的首席运营官。想跟读,去练习