Выбрать между временами: Present Perfect или Present Perfect Continious

1. Steve ... (feel) quite depressed recently, so he is thinking of taking a week off to go skiing.
2. I ... (know) Professor Johnson since my first year at college.
3. Tom ... (wait) for the bus for nearly an hour and it hasn't come yet.
4. "I ... (always/live) in this town and I don't intend to leave now", said the old lady.
5. Her eyes are red because she ... (work) on the computer all morning.