Câu trả lời:
1. I am not a bird, so I can't fly.
If I were a bird, I could fly.I can't fly because I am not a bird.2.She is my elder sister, so I must help her.
Because she is my elder sister, I must help her.I have to help her because she is my elder sister.3.They will get better, so we will be happy.
We will be happy when they get better.If they get better, we will be happy.4.Many people will come to the party, so you have to prepare enough food.
You must prepare enough food because many people will come to the party.Since many people will come to the party, you have to prepare enough food.5.He didn't say hello, so no one greeted him.
No one greeted him because he didn't say hello.If he had said hello, someone would have greeted him.6.I didn't feel well, so I didn't go with them.
I didn't go with them because I didn't feel well.If I had felt well, I would have gone with them.7.They live in the capital city, so they get many good chances.
Because they live in the capital city, they get many good chances.They get many good chances because of living in the capital city.8.She left early, so she didn't meet us.
She didn't meet us because she left early.If she hadn't left early, she would have met us.9.If he had told me about your trouble...
I would have helped if he had told me about your trouble.Had he told me about your trouble, I would have helped you.