Here are the correct choices for each pair of sentences:
a. The engine is making a strange noise. What is it? b. We live near a busy road so there's a lot of noise.
a. Light comes from the sun. b. I thought there was somebody in the house because there was a light on inside.
a. I was in a hurry this morning. I didn't have time for breakfast. b. We really enjoyed our holiday. We had a great time.
a. Can I have a glass of water, please? b. Be careful. The window has been broken and there's broken glass on the floor.
a. We stayed at a hotel. We had a very nice room. b. We have a big garage. There's room for two cars.
In summary, the correct forms are indicated as follows:
- a, b
- a, b
- a, b
- a, b
- a, b