Their songwriting has matured.是什么意思？

Their songwriting has matured.

他们的歌曲创作水平已经成熟。

their

pron. 他（她，它）们的，在提及性别不详的人时，用以代替 him 或 her；

例句
Their permissiveness toward their children reflects the wild abandon of their own lives.
他们对孩子的放任折射出他们自身生活的放浪形骸。

songwriting

歌曲创作；

例句
Their songwriting has matured.
他们的歌曲创作水平已经成熟。

has

v. 有( have的第三人称单数 )，（亲属关系中）接受，拿，买到；

例句
...the operation a patient has had.
病人做过的手术

matured

v. 成熟，长成( mature的过去式和过去分词 )，（票据等）到期，（情感和认识）成熟，使（技能或素质）成熟；

例句
When the trees matured they were cut in certain areas...
在有些地方，树木长成后就会被砍掉。