2 Underline the correct form of the present perfect in italics. It may be
possible to use both forms.

1 I’ve sent / been sending the invoice three times but they still haven’t paid.
2 It’s a successful business; they’ve opened / been opening eighty
branches in the last three years.
3 How long have you worked / been working here?
4 I’ve tried / been trying to get through all day but the number is always
engaged.
5 How much holiday have you taken / been taken this year?