Exercise 5. In each of the following sentences, put the verb in brackets into the correct form:

1. Two weeks (go) ....... fast when you are on vacation.

2. The cost of all these articles (have) .......  risen.

3. Three kilos of potatoes (make) ....... the basket heavier.

4. Some of the tables in the classroom (be) ....... broken.

5. Bacteria of the harmful kind (cause) ....... diseases.

6. What we need most (be) ....... books.

7. The English (be) ....... proud and independent people.

8. The United States (have) ....... a population of 250 million.

9. There (be, not) ....... any letters in the mail for you today.

10. Everyone in both cars (be) ....... injured in the accident last night.

11. The books borrowed from the library (be) ....... on my desk.

12. No news (be) ....... good news.