When we arrived the party was already in full swing.

我们赶到时，聚会已进入高潮。

When we returned, the party was in full swing and the dance floor was crowded.

我们回来的时候，聚会正开得起劲，舞池里挤满了人。

Spring ploughing is in full swing.

春耕闹得正欢。

Spring 1970. The social revolution was in full swing.

1970年的春天，社会变革潮起云涌。

At this time last week, the Nuclear Renaissance was in full swing.

上周的这个时候，核复兴正处于全盛时期。