Fill in the blanks with when, while, because, since, if, unless, before, after, wherever, although, so that, or as if.

1. When Edison invented a lamp which conducted electricity, gas had been the chief
    means of lighting home and streets.
2. I saw an old friend of mine while I was entering the building.
3. Though his car was much too small, he decided to sell it.
4. He won't pass the examination unless he study harder.
5. Wherever he went, he was warmly received.
6. That executive acts as if he owns the company.
7. If I get the money on time, I can go on my vacation.
8. Although she spend a lot of money on clothes, the never seem to suit her.
9. I have a lot of extra work to do because my assistant is on vacation.
10. Since they moved into an expensive apartment, they have become very snobbish.
11. When someone broke into her house and stole her jewelry, she was next door
      chatting with her neighbour.
12. It's because warm today so that I'm going to the beach.
13. Though my uncle has worked hard all his life, he could never save up enough
      money to go on a long vacation.
14. We will go to the theatre with you tonight if we can get a baby-sitter.
15. Don't give this package to him before he sign a receipt for it.
16. We're as pleased with these new towels so that we're going to buy some more.
17. After Hitler believed that Germans were the master race, he ste out to conquer all
      of Europe.
18. When I was in South America last year, I learned to speak Spanish.
19. He looks as if he hasn't ever changed his clothes.
20. Repairs will be made if they are necessary.