2017年春节期间，北上广深这些一线城市都至少有一半的人返乡过年，其中一些金融行业从业人员多选择高效便捷的交通方式。深圳的空城率达到69%，为四城最高，堪称名副其实的“空城”。据此完成下面小题。

C

My name is Mary. I am an English girl. I'm twelve. My dad and mom are English teachers. I have a brother. His name is Tom and he is thirteen years old. We are in China now. Tom and I are in Beijing No.4 Middle School. Tom is in Class 4, Grade 8 and I am in Class 9, Grade 7.I have a dog. It looks strong(强壮的)．It has a big mouth and two black ears. We have many Chinese friends here. They are kind(和善的).

根据短文内容，判断正误。

After decades of effort, the city is still trying to________how to ban smoking in public places.