当被问到想吃什么时，他只是犹豫地重复说着'哇哇'。

When asked what he wanted to eat, he just kept saying '___wah-wah' in hesitation.

他在演奏时使用哇音踏板制造出独特的音效。

He used a ___wah-wah pedal to create unique sound effects while playing.

婴儿开始不停地哭，发出'哇哇'的声音。

The baby started crying continuously, making a '___wah-wah' sound.