play the part of

In the play, Mary is playing the part of the dancer and doubling as the mother.

玛莉在剧中扮演那名舞蹈演员，兼演剧中的母亲。

The Mid-Autumn Festival eve, large-scale really plays the part of practices in namely, one batch of naval vessel anxious need oil, water, nonstaple food supplies.

中秋节前夕，一场大规模实装演练在即，一批艇急需油、水、副食补给。