We are studying in a very large classroom now => The classroom which....... In spite of his good salary , he was unhappy in his job -> Although................. We will live a happier and healthier life but we have to keep our environment clean —> If we...........

1. The classroom which we are studying in now is very large.

- which : dùng để thay thế cho những từ chỉ vật

2. Although he had a good salary , he was unhappy in his job.

- Although / Even though / Though clause , clause : Mặc dù ... , ...

= In spite of / Despite + V-ing/N/N pharase , clause : Mặc dù .. , ..

-> Mệnh đề nhượng bộ.

3. If we keep our environment clean , we will live a happier and healthier life.

- Câu điều kiện loại 1 : If + HTĐ ( S + V(s/es) ) , S + will/can/... + V-inf

-> Câu điều kiện có thật , có thể xảy ra ở hiện tại hoặc trong tương lai.