Hi,
are the following sentences correct, please? I'm just wondering if the new words I've learned fit perfectly in each sentence. Additionally, could you offer synonyms of the underlined words, please? I'd prefer it if native speakers could check this task.

1) He could hardly
retain his tears for his pet had passed away.
2) He fainted on his way to home, but after a moment he
sprung to his feet, pretending as if nothing happened.
3) He
flinched back in sheer horror as he caught sight of the corpse.
4) They quickly
scrambled out of the car in order not to miss the train.
5) David was
scouring for a suitable car thoroughly on the Internet.
6) He tried to please her with gifts but I'm afraid he
overdid flattering and eventually became a bit nosey.
7) He
scraped the decayed/rotten food from the bowl into the sewers.
(what's the difference between decayed and rotten food?)8) I accidentally
trod on a cat and it
scurried away.
9) We were
plodding through a big mass of mud when we finally spotted the cottage we were looking for.
10) The
assets are handed down from generation to generation.
Thank you very much in advance!