A、they are indispensable to people’s social well-being
B、they awaken people’s desire to exchange resources
C、they help people to cope with life in the information era
D、they can cure a range of illnesses such as heart disease, etc
A、they are indispensable to people’s social well-being
B、they awaken people’s desire to exchange resources
C、they help people to cope with life in the information era
D、they can cure a range of illnesses such as heart disease, etc