According to plate tectonic theory, what happens when two continental plates collide?

What is any method of measuring the age of an object or event in years, such as using atomic half-life?

Which of the following may one conclude from a map that shows the average ph value of rainfall in the u.s.? acid rain is a more serious problem on the east coast. acid rain falls equivalently across the continental u.s. there are more factories on the west coast. the midwest has fewer forests than the rest of the u.s.

9. technology can bring both good and bad things. building a vertical farm can increase food supplies in cities (good), but it may cause unemployment in rural areas (bad). give another example of both the good and bad sides of a technological advancement (5 noints)