1) I would rather to do computer science.

2) It was not until last monday that he got his.

3) Without doubt this record will sell a lot of copies.

4) According to the salesman, my new car would be delivered next Wednesday.

1. I would rather prefer you to do computer science.
=> I would rather you did computer science.

2. He did not get his visa until last monday.

=> It was not until Monday that he got his visa.

3. This new record is certain to sell a lot of copies

=> There is no doubt that this new record will sell a lot of copies.

4. The sales man told me that my new car would be delivered next wednesday

=> According to the salesman, my new car would be delivered next wednesday.