Shared bikes ( 共享单车 ) produced by companies such as Mobike (摩拜单车) and ofo bring great convenience to people. They can take people anywhere the subway and bus don’t go and can be left anywhere in public for the next users. Users can lock( 上锁 ) or unlock them just by simply using their smart phone. The fee for one ride is 1 to 2 yuan. It is no doubt that shared bikes are becoming a new trend of transportation, which relieve ( 缓解 ) the traffic pressure and do good to the environment as well. However bad things happen. Some people damage the QR code ( 二维码 ) on the bike, or use their own lock, which causes troubles to other users. What I want to say is that we’d better take good care of public service to enjoy the benefits of shared bikes.