Correct the following sentences:

1- you have to pay the tickets in advance.
you have to pay forthe tickets in advance.
2-psychologist point the importance for children of having contact with both parants.
psychologist point at the importance for children of having contact with both parants.
3- is there a possibility to find a cure for AIDS?
is there a possibility for finding a cure for AIDS?
4- i have more possibility to travel than my parents did.
i have more opportunity to travel than my parents did.
5-your advertisement doesn't precise whether flights are included in the price.
your advertisement doesn't explain whether flights are included in the price.
6-he promised to his mom he would clean his room.
he promised his mom he would clean his room.
7- I decided to accept the job proposal.
I decided to accept the job offer.
8-as you don't have much time, I propose you fly to paris.
as you don't have much time, I suggest you fly to paris.
9- could you provide us a list of hotels in the area?
could you provide us with a list of hotels in the area?
10-we weren't allowed to make any questions.
we weren't allowed to ask any questions.
11-the project has now reached to the final stage.
the project has now reached the final stage.
12-i wrote a letter to require more information.
i wrote a letter to ask for more information.
13-the price of gas is raising.
the price of gas is rising.
14- we had seat at the back row
we had seat in the back row