1. The man that we are talking about is a famous scientist.
> The man about...whom we are talking is a famous scientist.
2. The tree that we picked these fruits from is in front of the house.
> The tree from... which we picked these fruits is in front of the house.
3. The city that we were born in is very large.
> The city in... which we were born is very large.
4. Do you remember the day? We first met on that day.
> Do you remember the day on... which we first met.
5. The manager has just announced his retirement. We have all depended on him so much.
> The manager on... whom we have all depended so much has just announced his retirement.
6. The officer wasn't very friendly. I spoke to him yesterday.
> The officer to... whom I spoke yesterday wasn't very friendly.
7. The dog was very frightened. The boys threw stones at it.
> The dog at... which the boys threw stones was very frightened.
8. The road was built in 1980. We are driving on it.
> The road on... which we are driving was built in 1980.
9. Did you see letter? It came yesterday morning.
> Did you... the letter coming yesterday morning?
10. This is Red Hotel, and it is the biggest hotel in the city.
> This is Red Hotel, which... is the biggest hotel in the city.