Your task is__to find__(find)the cost of the hotel .为什么用to f

英语题!句型
1.When he got to the station, only _to find_ that the train was pulling out .这里为什么用to find?
2.By the end of next month, we_ will have found_ a good solution to the technical problem.这里为什么用will have found?

Tom is always the first _______ the ansewer.答案为什么是to find?这个句子是什么结构?

A man came home from work late,tired,to find his 5-year-old son waiting for him at the door.
“Daddy,how much money do you make an hour?”“If you must know,I make $20 an hour,”
“Oh,”the little boy replied,with his head down.He thought for a moment,looked up and said,“Daddy,could you lend me $10?”
The father was furious,“If you asked for the money to buy a toy or some other rubbish,then go straight to your room and think about why you are being so selfish(自私)!”The little boy quietly went to his room and shut the door.After about an hour or so,the father calmeddown,and started to think,“Maybe he really needs to buy something and he didn’t really ask for money very often.”So he went to the little boy’s room.“Sorry!Maybe I was too hard on you just now.”said the man,“Here’s $10.”
“Oh,thank you,Daddy!”he said happily.Then,the boy took out some coins.When the father found that the boy already had money,he got angry again.
“Why do you want more money since you already have some?”the father shouted angrily.
“Because I didn’t have enough,but now I do.”the little boy replied,“Daddy,I have $20 now.Can I buy an hour of your time?Please come home early tomorrow.I would like to have dinner with you.”
()48.How much does the boy’s father make an hour?______
A.$10 B.$20 C.$30 D.$40
()49.In this passage,the underlined word “furious” means ______
A.very angry B.quite happy C.too excited D.a little nervous
()50.At first,the father refused to lend the boy any money because ______
A.he thought the boy wanted to keep the money for himself
B.he thought the boywould buy something of useless(无用)
C.the boy always borrowed money from him
D.the boy reallyneeded to buy something
()51.The boy wanted to buy ______ withsome money
A.a new book for himself B.a nice present for his father C.somethingof no use D.an hour of his father’s time
()52.From the passage,we can infer(推断)that the boy’s father ______
A.often played with his son B.spent little time with his son
C.often came back home early D.often had dinner with his son
我要题目的答案和这题为什么要这么写就是语法或句型,大家一定要帮我,很快要开学了!

下面这句话,为什么用finding而不是to find,分析一下这句话的语法,全面一点
There is vast likelihood that students nowadays have difficulty finding employment after leaving school.
There is vast likelihood that students nowadays have difficulty findingemployment after leaving school.