College entrance examination Chinese sentence cohesion questions. (2013 New Curriculum Standard Volume 1), please explain

Your understanding is correct. The subject of 6 is consistent with that of 2, which is "work". However, 1 is used as a supplement to the second sentence. You can add a dash to understand it, which is used to explain the second sentence. The word "details". Or you can think backwards, first sort out the order of 45263, and then consider where 1 should be placed - (like this dash) "trivial things" correspond to "details". Hope this helps.