BY 11 O’CLOCK I WILL HAVE BEEN SURFING THE NET FOR FOUR HOURS

18:~A: "..." ~B: Yes. By 11 o’clock I will have been surfing the Net for four hours.A.Will you please leave the Net, Doris?B.Don’t you surf the Net every day, Nelly?C.You’ve been surfing the Net all morning!D.I wonder what’s made you put your heart and soul in the Net!