=>
1. If you leave the lights on all night, you will waste the electricity.
2. The thief runs faster than the policeman.
3. This is the first time I have seen this man here.
4. I wish I were tall enough to play volleyball.
5. A new style of jeans has just been introduced in Vietnam.
6. I began studying English 3 years ago.

7. The man used to play tennis when he was young.
8. Although I missed the bus this morning, I did not go to school late.
9. Unless he comes, we will go without him.
10. The girl who answered the phone was very polite.

1. leave the lights on all night and you will waste the electricity.

If the lights are left on all night, the electiccity will be wasted.

2. The policeman does not run so fast as the thief.

=> The thief runs faster than the policeman.

3. I have never seen this man here before.

=> This is the first time i have ever seen this man here

4. What a pity. I am not very tall to play volleyball.

=> I wish i were tall enough to play volleyball

5. They have just introduced a new style of jeans in Vietnam.

=> a new style of jeans has just been introduced in VN

6. I have studied English for 3 years.

I began studying English 3 years ago

7. The man often played tennis when he was young.

=>The man used to play tennis when he was young.

8. In spite of missing the bus this morning, I did not go to school late.

=> Although i missed the bus this morning, I did not go to school late.

9. If he doesn't come, we will go without him.

=> Unless he comes, we will go without him.

10. The girl was very polite. The girl answered the phone.

=> The girl who answered the phone was very polite.