他熟练地拨动吉他弦。

He skillfully ___strums the guitar strings.

他随意拨弄着吉他的琴弦，弹奏着一首简单的民谣。

He lazily ___strums the guitar strings, playing a simple folk song.

他轻轻拨动吉他弦，发出悦耳的声音。

He gently ___strums the guitar strings, producing a pleasant sound.