通则

general rule / general principle

to go through / to know well / (suffix) expert / to connect / to communicate / open / to clear / classifier for letters, telegrams, phone calls etc

classifier for an activity, taken in its entirety (tirade of abuse, stint of music playing, bout of drinking etc)

(conjunction used to express contrast with a previous clause) but / then / standard / norm / principle / to imitate / to follow / classifier for written items

(literary) (conjunction used to express contrast with a previous clause) but; then / (bound form) standard; norm / (bound form) principle / (literary) to imitate; to follow / classifier for written items