Choose the underlined part that is incorrect in each of the following sentences. Then correct it.

My grandfather has gone to hospital last month. He is fine now.
1. has gone
2. to
3. is
Life expectancy has been very low in the past. Now it is higher.
1. has been
2. in
3. is
My father used to do a lot of exercise since he was young.
1. to do
2. exercise
3. since
I was ill last week, and didn't do much exercise so far this week.
1. was
2. didn't do
3. exercise