他把书包重重地扔在沙发上。

He ___plunked his backpack onto the couch.

她坐在沙发上心不在焉地拨弄着尤克里里。

She sat on the sofa ___strumming the ukulele absentmindedly.

硬币从口袋里掉出来，扑通一声落在地上。

The coin ___plunked onto the floor after falling out of the pocket.