What is '주''s meaning in this sentence? I encountered this sentence in my textbook as follows: 따라서 여가 활동도 휴식이나 수면, TV 보기, 감상, 관람 등 가볍게 할 수 있거나 시간을 많이 투자하지 않아도 되는 활동이 주를 이루었다. I tried to analyze the role and the meaning of '주', which stands between '활동이' and '이루었다', but I couldn't. If '주' in this situation means a week, it might be a little non-sense. I find some other meanings in dictionary but I couldn't find any appropriate answer for myself. Thank you so much for your help in advance.