1. Every year, Viet Nam exports millions of tons of rice.

⇒ Millions tons of rice are exported by Viet Nam every year

2. The zookeeper feeds the animals at the zoo every day.

⇒ The animals at the zoo are fed (by the zookeeper) everyday

3. Mary types letters in the office every day.

⇒ Letters are typed in the office by Mary every day

4. My father waters this flower every morning.

⇒ This flower is watered by my father every morning

5. Someone cut down the tree in the garden yesterday.

⇒ The tree was cut by someone in the garden yesterday.

6. They chose him as the best actor of the year.

⇒ The best actor of the year was chosen as him

7. The artist painted a huge picture to raise fund for the poor children.

⇒  A huge picture was painted to raise fund for the poor children by the artist

8. Their boss made them work very hard until midnight.

⇒ They were made to work very hard until midnight by their boss

9. Mr. Tam is painting his pictures with his patience.

⇒ Mr. Tam's pictures are being painted with his patience

10. Countries are finding a way to solve the problem.

⇒ A way is being found to solve the problem by countries

11. My mother is making “Special Chinese Fried Rice” in the kitchen now.

⇒ "Special Chinese Fried Rice" is being made in the kitchen by my mother now

12. She is doing her homework in her room at present.

⇒ Her homework is being done in her room at present

13. He was repairing his car at this time yesterday

⇒ His car was being repaired at this time yesterday

14. Linh was riding a bike when we saw her yesterday

⇒ A bike was being ridden by Linh when we saw her yesterday

15. They were building this house at 5 o’clock last Monday.

⇒ This house was being built at 5 o’clock last Monday