For each of the following sentences, change the subject of the verb to the plural, and change the verb so that it agrees with its subject. For example:
The beach is supervised by lifeguards.
The beaches are supervised by lifeguards.
The singer performs twice a week.
The singers perform twice a week.
The class was visiting the museum.
The classes were visiting the museum.
The vase has been filled with flowers.
The vases have been filled with flowers.
1. The box was empty.
2. The river flows to the sea.
3. The bush has grown in the last two months.
4. The hat was on sale.
5. The bench is made of stone.
6. The plant has been watered.
7. The hedge is being trimmed.
8. The process was invented last year.
9. The sketch is nearly finished.
10. The breeze was warm.
11. The wall is being painted.
12. The church is two hundred years old.
13. The bridge will soon be completed.
14. The carpet has been cleaned.
15. The branch is covered with ice.