8ze. EL PLURAL DEL SUSTANTIVO. THE PLURAL OF NOUNS (Tema III, desde la página 27 hasta la pagina 33 de Gramática Inglesa para Estudiantes Españoles)

8ze) Choose the correct form of the verb, singular or plural (Capítulo III, desde la página 27 a la página 33 de Gramática Inglesa para Estudiantes Españoles):

8ze) Choose the correct form of the verb, singular or plural (Capítulo III, desde la página 27 a la página 33 de Gramática Inglesa para Estudiantes Españoles):
1. The barracks (was/were) blown off its foundation and collapsed on the sleeping troops
2. You don't see the eyes because the glasses (is/are) reflecting
3. The jeans (is/are) skintight
4. Police (is/are) investigating a series of traffic accidents
5. Cattle (is/are) kept for meat and milk
6. Outside the front door of his house a group of men (was/were) talking quietly
7. A number of changes (was/were) made to the system of stabilization