A jet stream forms high in the upper troposphere between two air masses<span> of very different temperature. The greater the temperature difference between the air masses, the faster the wind blows in the jet stream.
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So "Differences in temperature between two air masses" is the answer
For the answer to the question above, the answer is "Systemic Acquired Resistance''.
<span>it is a whole-plant resistance response and it occurs by following an earlier localized exposure to a pathogen. It is analogous to the innate immune system that can be found in the animals, and there is also an evidence that SAR in plants and innate immunity in the animals may be evolutionarily conserved.</span>
The anatomical term meaning away from the midline is lateral
the biome that is found at the biomes is called tundra
