请说明理由!1.You know,I ________ (look) for a job for three months,and this is my first formal interview.2.My sister ________ (stay) in Beijing for three months last year.3.The little boy is dirty all over because he ________ (play) in the mud all the morning.4.I ________ (wonder) if you were free this afternoon.5.Here he is!We ________ (wait) anxiously for him since last night.1.— I’m sure Andrew will win the first prize in the final.— I think so.He _____

请说明理由!
1.You know,I ________ (look) for a job for three months,and this is my first formal interview.
2.My sister ________ (stay) in Beijing for three months last year.
3.The little boy is dirty all over because he ________ (play) in the mud all the morning.
4.I ________ (wonder) if you were free this afternoon.
5.Here he is!We ________ (wait) anxiously for him since last night.
1.— I’m sure Andrew will win the first prize in the final.
— I think so.He ________ for it for months.(2008江苏)
A.is preparing B.was preparing
C.had been preparing D.has been preparing
2.—I have got a headache.
—No wonder.You_________ in front of that computer too long.(2007江西)
A.work B.are working C.have been working D.worked
3.The unemployment rate in this district_______ from 6% to 5% in the past two years.(2007上海)
—I am tired.I _______ the living room all day.
A.has fallen B.had fallen C.is falling D.was falling