How does a warm front form?

a. warm air becomes caught between cold air masses.
b. two air masses meet and stay separated.
c. warm air moves over cold air and replaces it.
d. cold air moves under warm air and pushes it up.

Plz asap can someone find the answer or the mark scheme or anything plzzz you : ) ‘it's perfectly understandable that hundreds of millions of people around the world live close to volcanoes’ use evidence to support this statement. (6 marks)

How have ethnic groups shaped the population in central america and the caribbean? how has migration shaped the population in central america and the caribbean? how has small land areas shaped population in central america and the caribbean? how has a rapid population growth shaped the population in central america and the caribbean?

Using plate tectonics and elastic rebound theory, describe why juan de fuca plate subduction produces so few earthquakes. what will happen in the future?