Singular or Plural?

1. This pair of sunglasses (be) really expensive. I'm not paying that much!

2. These scissors (be) blunt. Get me another pair.

3. That jacket you're wearing is really nice but those green jeans (be) horrible.

4. Physics (be) the study of the natural world.

5. A lot of the news we hear on the TV (be) bad. It's so depressing.

6. The police (investigate) a break-in at the National Bank last night.

7. People (be) are always likely to tell lies to protect themselves.

8. Think carefully before you spend that amount of money. A thousand pounds (be) a lot!

9. You should try walking so far just to find an open supermarket! Three miles (tire) you out so quickly, I'm telling you!

10. They have exaggerated a little with that new swimming pool. Did you see the temperature of the water? Forty one degrees (be) too high!