1. I think the reason [who-where-why-when] we get on so well is that we both enjoy talking.
2. The land is very fertile in the area [which-who-whom-where] Jack has bought his farm.
3. The walls are all [which-that-who-whose] remain of the city.
4. Is there anything [that-which-who-whom] I can do to help?
5. She is one of the kindest people [that-which-who-whom] I know.
6. A friend of mine [whose-who-which-whom] is a solicitor helped me.
7. The thought of going home to his family was all [who-which-that-where] kept him happy while he was working abroad.
8. There was a little [who-that-when-whom] we could do to help her.
9. Dorothy said something [who-where-which-where] I could not hear clearly.
10. We were told that we would be held responsible for anything [who-that-where-which] went wrong.
11. He is probably the best golfer [who-that-which-where] I have ever played against.
12. We received an offer of $80,000 for the house, [that-who-which-where] we accepted.
13. One of the people [who arrested - arresting - arrested - who arresting] was Mary Arundel, who is a member of the local council.
14. The book won't be published until next year, [that-which-when-who] is very disappointing.
15. I have to go to hospital on Monday, [that-when-which-who] means I won't be able to see you.
16. The bank was robbed by a group of men, three of [who-whom-where-which] were said to be armed.
17. The President has made many visits to Japan, the most recent of [whom - that - which - when] began today.

In this exercise, we need to fill in the blanks with appropriate relative pronouns or connectors. These words help to join sentences or clauses together, making sentences more complex and informative. Here's how each sentence can be completed:

The reason why we get on so well is that we both enjoy talking.
- 'Why' is used to provide a reason.
The land is very fertile in the area where Jack has bought his farm.
- 'Where' refers to a place.
The walls are all that remain of the city.
- 'That' is used to introduce a defining clause.
Is there anything that I can do to help?
- 'That' is used for defining clauses with objects such as 'anything.'
She is one of the kindest people that I know.
- 'That' can follow words like 'kindest' to introduce defining clauses.
A friend of mine who is a solicitor helped me.
- 'Who' is used for people.
The thought of going home to his family was all that kept him happy while he was working abroad.
- 'That' introduces a defining clause related to 'all.'
There was a little that we could do to help her.
- 'That' is used to define 'little effort' or assistance.
Dorothy said something which I could not hear clearly.
- 'Which' can be used to introduce a subordinate clause.
We were told that we would be held responsible for anything that went wrong.

'That' is used with non-specific objects like 'anything.'

He is probably the best golfer that I have ever played against.

'That' can refer to people in defining clauses.

We received an offer of $80,000 for the house, which we accepted.

'Which' refers to the offer and introduces a non-defining clause.

One of the people arrested was Mary Arundel, who is a member of the local council.

'Arrested' functions as an adjective here to describe 'people.'

The book won't be published until next year, which is very disappointing.

'Which' refers to the entire preceding clause and is used in non-defining clauses.

I have to go to hospital on Monday, which means I won't be able to see you.

'Which' refers to the hospital visit and is used in non-defining clauses.

The bank was robbed by a group of men, three of whom were said to be armed.

'Whom' is used as the object of a verb or preposition referring to people.

The President has made many visits to Japan, the most recent of which began today.

'Which' refers to 'visits' and introduces a non-defining clause.