play（up）on
1．perform on a musical instrument演奏（乐器）
He was playing an old tune on his flute．他正用笛子吹奏一首老曲子。
2．cause an effect on；influence影响
The TV film played on his feelings．这部电视剧震撼了他的感情。
The cries of the baby at night played on my nerves．夜间婴儿的哭声闹得我烦躁不安。
3．utilize利用
He played on her good nature to borrow some money from her．他利用她的善良向她借了些钱。
The speaker knew how to play on the audience's feelings．这位演说者懂得怎样利用听众的情绪。