A.Making new discoveries in the electronics industry. B.Designing printers. C.Selling printers. D.Looking for successful products and find out the reasons.
【简答题】Every mobile phone has a ringtone(铃声). It tells you that someone is calling you. Now, there _ a ringtone called “mosquito tone(蚊子铃声)”. Mosquito tone has a special . Only children and agers can he...