Ing or infinitive?

I should fill the gaps with correct form of infinitive or ing forms. Could you check it please?

We will never forget our .....................travelling across Asia.
She sent the e-mails, and then went on.................... watching TV.
As a child I used to spend a lot of time ...............swimming.
She was the first ................finishing the race.
On the train I met a pensioner who said he .................. had been working for the British Rail for 30 years.
When driving in the rain I am afraid ................................ to skid.