Conversion of Compound (Double) sentences to Simple sentences

Compound. -- He finished his exercise and put away his books.
Simple. -- Having finished his exercise, he put away his books.
Compound. -- Not only did his father give him money, but his mother too.
Simple. -- Besides his father giving him money, his mother also did the same.
Compound. -- He was a mere boy but he offered to fight the giant.
Simple. -- In spite of his being a, mere boy, he offered to fight the giant.
Compound. -- He must not be late, or he will be punished.
Simple. -- In the event of his being late, he will be punished.
Compound. -- You must either pay the bill at once or return the goods.
Simple. -- Failing prompt payment, the goods must be returned by you.
Compound. The men endured all the horrors of the campaign and not one of them
complained at all.
Simple. The men endured all the horrors of the campaign without one of them making
any complaint.
Compound. -- We must eat, or we cannot live.
Simple. -- We must eat to live.