25 present perfect/ past simple выберите правильную форму: is that a new mobile phone? yes, i've just bought/ i just bought it how much has /did it cost? it has cost/ cost £18 have you done/ did you do your homework yet? yes, i 've finished/ i finished it last night. what about you? no, i haven't finished/ didn't finish it yet i have started/ i started it yesterday but i've still got a lot to do.