Afast-flowing river of air that forms when two air masses of very different temperatures meet is called a a) el niño. b) jet stream. c) trade wind. d) sea breeze.

A fast-flowing river of air that forms when two air masses of very different temperatures meet is called B. jet stream.
These types of streams are often meandering, and can be found on some planets, not only the Earth. 

Um can u take a picture of the work

1. protection 2. homeostasis 3. storage4.blood formation5.bone marrow 6.movement