(49)「つながり・関係に言及する」のに役立つ定番表現

connection with/between … (・・・との関係、つながり)
cut and sever connections with the firm (その会社との関係を清算する)
make a connection between the two events (2つの出来ごとを関係づける)
It seems that there is a close connection between crime and poverty. (犯罪と貧困との間には密接な関係があるようだ)

次の「relation」より具体的な関係が強い言葉です。

relation/relationship/link between/among …(・・・の間の関係、関連)
There is no relation between crime and poverty. (犯罪と貧困とにはつながりはない)
Police suspect there may be a link between the two murders. (警察は2つの殺人の間には関係があると疑っている)

relation/relationship/link to …(・・・との関係)
The pulse has a close relation to health. (脈拍は健康と密接な関係がある)