Page 10 -

Grammar Focus

A Check the correct sentences.

1 a. Storms are a kind of severe weather that occur in all climates.
b. Storms are a kind of severe weather that occurs in all climates.

2 a. They start when a sudden drop in air pressure creates a vortex.

b. They start that a sudden drop in air pressure creates a vortex.

3 a. Tornadoes can form whatever a warm front meets a cold front.

b. Tornadoes can form whenever a warm front meets a cold front.

4 a. So many tornadoes touch down in the Midwest which is called
Tornado Alley.

b. So many tornadoes touch down in the Midwest when is called
Tornado Alley.

5 a. The strongest hurricane on record in the United States were Camile.

b. The strongest hurricane on record in the United States was Camile.

B Choose the correct words to complete the sentences.

1 A warm front rises through a cold front and ( make / makes ) a tall cloud.

2 They start ( what / when ) a sudden drop in air pressure creates a vortex.

3 It is ( so / very ) powerful that it makes a loud crash of thunder.

4 Hurricanes are the strongest and ( dangerousest / most dangerous )
storms.

5 She was a category 5 storm that ( blew / blows ) winds over 300 km/h.

16