1. Because of their lateness, these pupils can't enter school.
Because they are very late for school, these pupils can't enter.

2. Because there are differences in culture and civilization, they can't understand each other.
Because they can't understand each other, there are differences in culture and civilization.

3. Because of his laziness, Nick is often punished.
Because Nick is often punished, it is due to his laziness.

4. Because his leg was bad, he walked slowly.
Because he walked slowly, it was because of his bad leg.

5. Because of not feeling well, Mary didn't go to work yesterday.
Because Mary didn't feel well, she didn't go to work yesterday.

6. Because of the enormous crowd, we couldn't get into the disco.
Because we couldn't get into the disco, it was because of the enormous crowd.