Question

1.his parents were very happy because he passed his exam

=> If

2.They use gas because they think it cheaper than electricity

=>If

3.His friends were so late, so they missed the train

=>If

4.I couldn't tell you the truth because I made a promise

=>If

G i úp với ạ @@

Answer 1

1 If he passed his exam, his parents were very happy

2 If they think gas cheaper than electricity, they use it

3 If his friends missed the train, they were so late

4 If I made a promise, I couldn't tell you the truth

Answer 2

1.his parents were very happy because he passed his exam

=> If he hadn't passed his exam, his parents wouldn't have been happy

2.They use gas because they think it cheaper than electricity

=>If gas weren't cheaper than electricity, they wouldn't use it

3.His friends were so late, so they missed the train

=>If his friends hadn't been so late, they wouldn't have missed the train

4.I couldn't tell you the truth because I made a promise

=>If I hadn't made a promise, I could have told you the truth