通俗

common / everyday / average

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)

custom / convention / popular / common / coarse / vulgar / secular

Dramatized history of successive dynasties (from Han to Republican China) by Cai Dongfan 蔡東藩|蔡东藩

Dramatized history of Republican China until 1927 by Cai Dongfan 蔡東藩|蔡东藩, and later chapters by Xu Qinfu 許廑父|许廑父

to put it in simple terms, ...

popular fiction / light literature

easy to understand

popular science