it was a letter to cheer them up. 中的it起什么作用?

it was a letter to cheer them up. 中的it起什么作用? 1.( )you have been looking forward to.A.The letter is that B.The letter is hereC.Here the letter is D.Here is the letter2.( )Adam Smith's The Wealth of Nations that Jim Green was fascinated by economic theory.A.After reading B.It was reading C.It was It was great to receive a letter from you two days ago同义句 well,here is the letter he wants to _______.he was very busy.A.have it to be typed.B .have typed.C.have it typed D.type it为什么不选C It was the letter you'd been___.A.waiting B.desiring C.expecting D.hoping it was nice to get your last letter什么意思 have you found out __yes,Mr.Brown said it was for Mrs.White.A.whose letter is it B.who receives the letter C.where the letter is D.who has written the letter Would it be any trouble for you to bring the letter to Mr.Wang?No.I_____him this evening.A am about to see B was to see C would see D shall be seeing It--------me 3 days to write the letter A.took B.takes C.spend D.spends It was she that wrote letter to us.错误?书本上印的是否有错It was she that wrote letter to us.letter前面为什麼没冠词? He preferred to write the letter by hand____.A to typing it B than type it C to type it D rather than type it I tired to wake up my wife by knocking at door ,but she was fast a----A traffic accident h---to us,but luckily no one was hurtI have just r-----a letter ,Itsfrom SusanWhat p--- should .I get her for her beithday Its too bark to see c---.Why not tur -Was marry still angry with me --To tell the truth ,----reading your letter ,she did not open it.A but for B far from C rather than D no wonder Read the letter and him 选择哪个?为什么?A pass it to B pass on it to C pass it on D pass on it 4.Read the letter and ____ him.A.pass it on to B.pass on it to C.pass it for D.pass it on read the letter and___ himRead the letter and___ himA pass on it to B pass it on to C pass it on D pass it for,A ,C 呢 ---Sorry,I forgot to bring you the letter.---That's all right._______.A.I will go to get it myselfB.I was going to get myselfC.I will go to get myselfD.I was going to get it myself ()the letter ,i went out to post it.A.writing B.having written C.to write D.written