The Italian way is to round off a meal with an ice-cream. [VERB PREP. noun]

意大利人总是在用餐结束时来份冰激凌。

...a dazzling firework display which rounded off a lovely day. [VERB PREP. noun (not pronoun)]

为美好的一天画上圆满句号的绚烂烟花

This rounded the afternoon off perfectly. [VERB noun PREP.]

这使得下午的活动圆满结束。

He rounds off by proposing a toast to the attendants. [V P + by]

他向来宾祝酒，圆满结束了活动。