"How has your home town changed since you were young?" In which part will the above topic be presented in the section of Speaking?

A  alter table student  add constraint sex_df  default  '男'  for sex
B  alter table student  add constraint  default  '考查'  for  sex
C  alter table student  add constraint  default  '男'  for  sex
D  alter table student  add    default  '男'  for  sex

A、沪昆线
B、大秦铁路
C、京津城际
D、京广铁路