<h2>Answer: Option D</h2><h2 />
Option A, "a large swirling, low-pressure system that forms over the warm Atlantic Ocean" is incorrect because tornadoes do not form over water. That would be a hurricane.
Option B, "a winter storm with wind speeds of at least 56 km/h and low visibility" Is incorrect because tornadoes do not form in cold weather. That would be a blizzard.
Oa boundary between two air masses of different density, moisture, or temperatureption C, "a violently rotating column of air in contact with the ground" is correct <u>because tornadoes are columns of air that rotate due to warm air and cold air colliding.</u> They usually occur during a thunderstorm.
Option D, "a boundary between two air masses of different density, moisture, or temperature" is incorrect because tornadoes are not based on air mass, density, moisture, or temperature. This would be a front.
Answer:
That is much less often than in the last 150 million years, when the field has flipped every 600,000 years. In the last 10-20 million years it has sped up even more, to once every 200,000-250,000 years. "The evidence points to a more stable field in the very far past and fewer reversals," says Veikkolainen.
the comprising of monies gotten from different governments and that can incorporate gifts, shared expenses, and unexpected credits and advances.