Find the mistake in the sentence.
1.Your uncle works in Ha Noi for one year and then moved to Da Nang, didn't he?
2.I spent fewer time on the first question than the second one.
3.Many Americans are choosing to have less children because of their low incomes.
4.Jenny and Natalie are the members of the Photography Club, don't they?
5.You could ride a bicycle when you were five, weren't you?
1. works -> worked
2. fewer -> less
3. less -> fewer
4. don't -> aren't
5. weren't -> couldn't