完形填空

　　  Some people say they have an answer to the problems of car crowding and pollution. In many cities, hundreds of people ride bikes to work every day. In New York City, some bike riders have even  1    a group： Bike for a Better City. They say if    2    people rode bikes to work, there would be fewer cars and less dirty air.

        For several years this group has tried to get help for bike riders. They want to have special roads for bikes only, because when bike riders must use the same roads  3     cars, there may be accidents. Bike for a Better City feels if there were bike roads, more people would use bikes.

        But    4    bike roads have been ready yet. Not everyone thinks it is a good  5     . Drivers don't like it, and some shop owners don't,    6  . And most people live    7    far from the city to travel by bike. Still,    8    has been done about it. On Saturdays and Sundays, the largest open park in New York is     9     to cars, and the roads may be used by bikes only, but the group still says this is not enough and goes on fighting    10   bike roads.

曹某因违章停车被交警贴罚单处罚，为此，曹某在网上发帖称：“车刚停在那里，就被贴条了，交警真孬种。”警方认为“曹某公然对人民警察进行侮辱”，据此，警方对曹某处以行政拘留5日的处罚。“网友骂交警孬种被拘留”引发舆论高度关注，众多网友质疑警方处罚不当。近日，当地警方通过官方微博表示“经复查，认为对当事人处罚不当，依据有关法律法规，决定撤销该行政处罚决定，向当事人道歉，并向有关责任人进行问责”。其后，曹某在网上再次发帖表示接受警方道歉，并声明自己以后也要做遵纪守法的公民。
请运用所学知识，对材料中曹某和警方的言行进行辨析。 

根据卫生部《公共场所卫生管理条例实施细则》规定，我国自2011年5月1日起在公共场所全面禁烟。因为香烟中的尼古丁等有毒物质对人体的呼吸、神经等系统都会造成极大的危害。尼古丁主要存在于烟草细胞的哪一结构中（   ）。