Answer:
The mountains cause rainfall.
Step-by-step explanation:
The fact that the mountains run parallel to the coast is the key in the difference in climate between the two areas. Since they are parallel to the sea, they block the wind and moisture coming from the sea towards the land, the mountains cause this air to rise and when it hits the cold air at higher altitudes, it results in rain. This leads to the lush and tropical areas whereas without the parallel mountains to the coast, the amount of rain the area receives decreases, resulting in a desert like environment.
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