几道高中英语单选题,请英语大神瞧瞧

几道高中英语单选题,请英语大神瞧瞧
1.unless he ______the place before,he won't introduce it to us in such detail.
A.has visited B.visits C.visited D.was visiting
2.--i have received another message telling that i have won a prize in a lottery.
--don't come forward.you ______again.
A.are taken in B.should be cheated C.are being cheated D.must have taken in
3.--tom says he is too tired to go on.
--he can't be.He ______for an hour.
A.just worked B.has only been working C.has just worked D.had only been working