Put questions to the subjects of these sentences:
1. nick is my close friend. 2. brian and victor are
partners. 3. he knows a lot about cars. 4. they make
computer programs. 5. the policeman knows the code. 6.
my optimism helps me to live. 7. books give us a lot of
knowledge. 8. traffic jams are typical of big cities. 9.
computers make our work easier. 10. light travels fast.
11. alexander bell invented the telephone. 12. michael
saw an accident. 13. j. rowling wrote all the books about
harry potter. 14. my friends invited me to the karaoke
club. 15. something happened last night. 16. someone
came here yesterday. 17. his words made me change my
mind. 18. columbus discovered america. 19. somebody
took the files, 20. some people knew about their plans.