Beg for help! need help on fix the sentences

[chuckchuck123]

i have this fix the sentences homework, i turned it in and got a C on it, the teacher returned it to us and give us a chance to fix it again and hand it in to him on monday. Can someone please check for me what did i do wrong and maybe give me some suggestions. Thank you so much! The original sentence is in bold, my version of revision is Italic.

Then he thanks God it was only a dream. (2)
Then, he thanks God that it was only a dream.

The cars fell in to the crevices. (1)
The cars fell into the crevices

The tremendous impact hit the Southern part of Los Angeles exactly at 9:00 o’clock evening time…(2)
The tremendous impact had hit the southern part of Los Angeles at exactly 9’clock evening time.

Suddenly everyone was covered in debris….(2)
Suddenly, everyone was covered by debris….

After couple of hour the oxygen in the ship……(3)
After couple hours, the oxygen inside the ship……

She belives that a canal that goes trough the ocean….(2)
She believes there is a canal that goes trough the ocean….

The earthquake when on for about 5 min. (2)
The earthquake went on for about 5 minutes.

Upon arriving, the same thought occured the entire crew. (2)
Upon arriving, the entire crew shared/had the same thought.

By time they arrived it was too late. (2)
By the time they arrived it was already too late.

All of a sudden a strange thing started happening. (1)
All of a sudden strange things started happening.

All you can hear in the city was screams and cries…(2)
All you can hear from the city were screams and cries….

[Humble]

Hi, Chuck,
It seems the forum guidelines say one isn't supposed to do their homework here. Why not work it out yourself?
It's impossible for a teacher to see your weak points and teach you right unless you do your homework yourself. Making mistakes is not a tragedy, it's a necessary experience; it just shows where it hurts and enables to choose the appropriate remedy or treatment. We all learn from our mistakes.
Best wishes
Cheers

[chuckchuck123]

hello, i did my homework and handed to the teacher. This was returned to me graded, but the teacher didn't correct my mistake, he wants me to find the mistake myself. Obviously, i think i was right, and it's not. Therefore I turn to this forum for help because the only answer I know is the wrong answer. It's not like i am doing my homework here. I am seeking helps on what i did wrong. But i thank you very much for your advice.