The key answer of exercise 2

a)

1. She let him travel home on the subway in New York alone when he was nine years old.
2. Because he had been nagging her for weeks to be allowed out on his own and because she believes in encouraging independence.
3. She received support from some, and a lot of negative reactions from others. She was accused of being 'crazy' and 'America's worst mom'.
4. She thinks that if you are too over-protective then your children do not learn about danger and about how to take risks, which then becomes a danger in itself.

b)

1. independence
2. mollycoddle
3. deliberately; expose
4. reasonable risks; unsupervised
5. over-protective
6. risk-averse