看到考试成绩时，他的第一反应是开心地跳了起来。

His first ___reaction to seeing the test results was to jump for joy.

当这两种化学物质混合时，会产生剧烈的反应。

When these two chemicals mix, they cause violent ___reactions.

观众对这部电影的评价褒贬不一。

The audience had mixed ___reactions to this movie.

这位拳击手凭借快速的反应躲过了对手的重拳。

The boxer dodged his opponent's heavy punch thanks to his quick ___reactions.