The Doctor had his revenge, after all.

frequent adj。 happening often; habitual。 时常发生的；惯常的。

His role will most likely be to cover up the murder, as it has been so often in the past.

他的角色更像是掩盖谋杀罪行，过去也时常发生这样的事。

The Canadians saw a new, wider union, a potential new national institution or central government, as a possible solution for breaking out of this constant political disorder.

加拿大人认识到一个更为广泛的的联盟，一种可能的家制度或中央政府，可以作为避免这种时常发生的政治混乱的一个可行的解决办法。

In the Song Dynasty it often occurred that when somebody owed a grudge to a person the latter was accused, and banished, and then the escort was bribed so as to put him to death when passing through this forest.

宋代时常发生这样的情况：某人有仇，被人告发，流放，然后贿赂镖师，路过此林时将其处死。