这位拳击冠军在社交媒体上向对手发起了挑战。

The boxing champion posted a ___challenge to his rival on social media.

上周末我们在公园里即兴举办了一场舞蹈对决。

We had a spontaneous dance ___throwdown in the park last weekend.

她生气地把钥匙扔在柜台上转身离开。

She angrily ___threw down the keys on the counter and walked away.