Verified answer

Ex 3

1 haven’t seen 2 haven’t heard 3 has failed 4 has made 5 has been worrying 6 has been studying 7 hasn’t taken

Ex 4

1 are> have been 2 has been winning > has won 3 OK 4 they have taken the dog … 5 OK

Ex 5

1 My wife has been painting for five years, but she hasn’t sold a single painting yet.

2 I’m glad that we have finished the work

3 My hands are dirty. I have been working in the garden.