Convection takes place
a. warm air is more dense than humid air.
b. warm and cold air have the same densityc. cold air is less dense than warm aird. cold air is more dense than warm air

The correct answer is:  [D]:  "Cold air is denser than warm air" .

The scientist can conclude that there is a decrease in the natural resources due to human activities. because of innovation and modernization of the environment, then there goes pollution and other bad effects that destroys the natural resources.

Your answer is d. silli hope this ! : ) i left an explanation down below if you need it: a sill forms when hot magma squeezes between layers of rock to form a hardened sheet of rock. a sill is basically a tabular sheet intrusion between old layers of sedimentary rock, volcanic beds, or in the direction of foliation inherent in metamorphic rock. the word sill means a concordant intrusive sheet.