Positive stability can be illustrated by a ball inside of a bowl.

Some conditions require the use of airplane controls in order to return the airplane to the desired attitude.

The story "The Hobbit, or There and Back Again" written by the world-famous English writer J.R.R Tolkien in 1937.
The action of the book happening in the country "Middle Earth", populated by many characters of fairy tales and myths - dwarves, hobbits, goblins, trolls, elves.
The hobbit Bilbo, the country  stay-at-homea of a middle-aged man ,  is the main hero of this book.
Bilbo was persuaded by  magician Gandalf  and he goes on a journey full of dangerous adventures, along with a group of dwarves.
Dwarves  are going to return the treasure of their ancestors, which was captured by the evil fire-breathing dragon.  Dangers await to friends on their way as trolls, pirates, goblins troops but the dragon in itself became a dangerous enemy. 
However, thanks to the courage, skill and ingenuity of the main hero and his companions as well as helping their many friends, all the adventure end happily:  the dragon was defeated , the attack of goblins was stopped, and the main hero was sent to his home, along with a some share of treasures and with magic ring.

1. Tom could see his Grandpa working in the garden.
2. Ally saw the Rolls standing in the yard.
3. No one noticed Jim taking purse.
4. The family heard somebody shouting outside. It was Miss Turby.
5. I caught him stealing plums from my garden.
6. We found the safe locked and the papers stolen.
7. He reported the watch lost.

Предложения 8, 9, 10 правильно напечатаны? Мне кажется что, что-то не хватает!
8. She didn't have a bag any more. It was stolen
9. The windows of some of the houses were broken by the explosion
10. The soldier's right leg was amputated

11. I left my sisters talking about the film stars.
12. She was half asleep when she heard them knocking at the door.
13. Russel went over to the well and found the animal swimming in six feet of water.
14. Sam caught his kitten drinking milk
15. The sergeant watched the soldiers getting ready to fire the guns.