A.teacher
B.philosopher
C.psychologist
D.doctor
A.Multi-mesa messaging service
B.Mobile communications technology
C.Mobile communications service
D.Mobile communications technology and service
A.cell phones
B.computers
C.cell phone and computer
D.mobile phone and computer
A.SMS also sends rubbish short messages
B.SMS violates their privacy
C.SMS does not consider whether people need it or not
D.SMS doesn’t get people’s permission to send them messages