Extended version:
1.he/not work hard/he/not be promoted.
If he hadn't worked hard,he wouldn't have been promoted.
also
If he doesn't work hard, he won't be promoted.
2.she/know the correct answer/she/win the crash prize
If she had known the correct answer, she would have won the cash prize.
also
If she knew the correct answer, she would win the cash prize.
also
If she knows the correct answer, she will win the cash prize.
3.the firemen/not arrive so quickly/the fire/burn down/Mr Smith`s house
If the firemen hadn't arrived so quickly, the fire would have burnt down Mr Smith's house.
4.he/be/more careful/he/not/fall of his bike
If he had been more carefull, he wouldn't have fallen off his bike.
also
If he is more carefull, he won't fall off his bike.
5.he/not tell/the police the truth/they/arrest/him
If he hadn't told the police the truth, they would have arrested him.
also
If he doesn't tell the police the truth, they will arrest him.