The carbon dioxide content in the air that we exhale is about?A. 4%B. 9%C. 15%D. 16% 0 0 votesArticle Rating Subscribe LoginNotify of new follow-up commentsnew replies to my comments Label {} [+] Name* Email* Website Label {} [+] Name* Email* Website 0 Comments Oldest Newest Most Voted Inline FeedbacksView all comments
