Помогите пожалуйста не понимаю суть задания

Task 6.

Make one sentence using so, so that, because, as, since.

1) I didn’t phone you. It was very late.

2) I turned up the radio in the lounge. I could hear it in the kitchen.

3) The restaurant was full. We went to the bar next door.

4) I stayed at home. I was expecting a phone call.

5) It’s a very large city. You have to use public transport a lot.

6) I learnt to drive. My mother didn’t have to take me to the riding school every week.

Задание: нужно два предложения соединить в одно , используя so, so that, because, as, since.Например: 1).I didn’t phone you because it was very late.

1. I didn't phone you, because it was very late.2. I turned up the radio in the lounge, as i could hear it in the kitchen.3. The restaurant was full, so we went to the bar next door.4. I stayed at home, since i was expecting a phone call.5. It' a very large city, that so you have to use public transport a lot.6. I leaent to drive, so my mother ......должно быть так