To avoid risks associated with tornadoes, lightning, and hurricanes, in the United States you should steer clear of "Nevada", although the risks associated with these events are extremely low.
Answer: 1- (D)
2- Lithosphere
3- True
4- True
Explanation: Black smokers are generated in the mid oceanic ridges and during the underwater volcanic eruption, which is a hot vent releasing black colored smokes of sulfur from it. They are often associated with the Volcanogenic Massive Sulfide (VMS) deposits.
The lithosphere is the rigid broken plates that are relatively cool and flows over the weaker and viscous asthenosphere layer.
When the groundwater flow intersects the ground level, it forces the water to come out to the surface forming a spring.
The study of changing atmospheric composition along with the ice cores, helps in determing the age upto 800,000 years. But recently, a new discovery has made, in which the ice cores helped in dating back to about 1.5 million years.
Industrialisation. Or that's what I think
At the mouth of the river, or where the river's velocity slows too much to carry the sediments.