Exercise 1: Complete the conversation with the correct form of nouns given in the box.
Anna: What are you doing, John?
John: I'm writing (1) ___________ .
Anna: Oh, you have (2) ________________. Do you always write (3) _______________ on your computer?
John: Yes, but I'm not doing very well today. I've been working for about three (4) _________ now.
Anna: You've got lots of (5) __________ to help you, though. I don't have many books because I don't have much (6) ____________. Quite often I can't even buy (7) ____________.
John: Really? That can't be much (8) _____________.
Anna: I'd like to get (9) ___________________ to earn more money. I've got a few (10) ____________, but what do you think I should do?
John: My brother paints (11) _________________ and sell them. Why don't you do that?
Anna: Because I'm not good at painting.