Which relationship between two species listed would be mutually beneficial a) a fish and a leech b) a dog and a tick c) a flower plant and a bee or d) a tree and a caterpillar ?

The theories on the expansion of galaxies maybe re-examined to strengthen science should not be tested to strengthen science will weaken scientific knowledge if they change will become laws if they don't change

Explain the source of radioactivity in uranium in earth’s crust by which it produces nuclear radiation

How can an organ, such as the lungs, work for multiple body systems?