4.What is the probable relationship between 4 Bthe speakers?A.Sales assistant and customer.B.Flight attendant and passenger.C.Waitress and diner.听力材料Text4W:What can I do for you,sir?M:Can I have some orange juice,please?W:I'm afraid we've stopped serving food anddrinks now.Could you fasten your safety belt?We'll be landing soon.(4)