Complete the second sentence so that it has a similar meaning to the sentence printed before it, begin with the given word(s) or phrase

Ex1. Complete the second sentence so that it has a similar meaning to the
sentence printed before it, begin with the given word(s) or phrase.
1. You should review your lessons for the exam.
It’s time
2. When did you start working in that factory?
How long
3. Oil was slowly covering the sand of the beach.
The sand
4. He was sorry he hadn’t said goodbye to her at the airport.
He regretted
5. I advise you not to buy that car.
If