1. Wite a or an

1. ............ egg

2. ............... friend

3. ............... sink  

4. ................ arm 

5. ................ mouth .

6. ................. onion

7. .................. umbrella

8. ................... classmate

=> Answer: 

1. an    2. a       3. a      4. an     

5. a    6. an      7. an      8. a

2. Write a/ an or the.

1. My father is ......... doctor.

2 ..............Sun keeps........ Earth warm.

3. ............ dolphin is intelligent animal.

4. I have ............. orange shirt too.

5. My brother likes blue pen, not......... red one.

=> Answer: 

1. a      2. The/ the      3. The     4. an     5. the

3. Write the correct form of each verb in brackets.

1. If it (be) ..........  sunny next week, we (go) .............  on a picnic.

2. If we (recycle) ............  more, we (help) ............  the Earth.

3. We (save)...........  a lot of trees if we (not waste) .............. so much paper.

4. More people (have)......... fresh water if we (use) ....... less water.

5. If the river (not be) .......... dirty, there (be) ............ more fish.

=> Answer: 

1. is / will go       2. recycle / will help       3. will save/ don't waste

4. will have/ use     5. isn't/ will be

4. Combine each pair of sentences below to make a first conditional sentence.

1. The air isn't fresh. People cough.

2. The water is dirty. A lot of fish die.

3. We cut down trees in the forest. There are more floods

4. There is too much noise. People don't sleep.

5. There is no water. Plants die.

=> Answer: 

1. If the air isn't fresh, peoplee will cough

2. If the water is dirty, a lot of fish will die

3. If we cut down the trees in the forest, the will be more floofd

4. If there is too much noise, people won'r sleep

5. If there is no water, plants will die

5. GAME: Fun matching

=> Answer: Học sinh tham gia trò chơi trên lớp