Grace , I think from a logical view sentence 2 sounds a little strange because what that sentence is expressing is that Mr and Mrs Zhou were doing 2 completely separate things at the same time. Sitting was one activity and watching the movie was a completely different activity . But actually those two things , sitting and watching, were basically combined together.Thatb is why sentence 1 is better. 一边 V + 一边V means doing one thing while doing another thing at the same time . 边吃边聊 eat and chat 边喝边吃 drink and eat The first sentence is more correct because by sitting and watching the movie the two actions were combined as one. Can you see how "eating and chatting" are different from "sitting and watching" a movie? I hope this helps! I am sure our Chinese friends will have a better explanation than me ! But maybe at least you can get started understanding with my little explanation.

A: 周先生和周太太坐着看电视。 B: 周先生和周太太一边坐一边看电视 C:周先生和周太太一边坐着一边看电视 A, "坐着" means already sitting there. B, “坐” means from standing up to sit down. C, is same meaning with A.

V1着V2 —— focus on V2, “V1着”is the status of V2. and normally V1 is the kind of action processing stably or steadily. 一边V1一边V2——focus on both action. 一边坐一边看电视 —— where does this occur? or was it made up by you for your question?

Maybe i don't understand how to use "V1着+V2" in a sentence correctly. A: 周先生和周太太坐着看电视。 B: 周先生和周太太一边坐一边看电视。 Hi, in this scene, I think 坐着 is more like a adj, not a verb. Because it's describe how you watching TV. You sit, so you can watch comfortable. So B is wrong. But you can say, 他们一边聊天一边看电视。 Anyway, when my parents teach me to speak, they don't know what is verb or adj. Vers, adj, etc are just help foreginer to understand. I think it's better to find a language partner.

V1着V2 —— focus on V2, “V1着”is the status of V2. and normally V1 is the kind of action processing stably or steadily. 一边V1一边V2——focus on both action. 一边坐一边看电视 —— where does this occur? or was it made up by you for your question?