Which statement explains something that the fossil record indicates? A. Earth is 4.5 billion years old.
B. mammals have always existed on Earth.
C. Mass extinctions have occurred several times on Earth.
D. The amount of water on Earth has decreased over time.

Part a constants huck finn walks at a speed of 0.60 m/s across his raft (that is, he walks perpendicular to the raft's motion what is huck's velocity (speed and direction) relative to the river bank? express your answer to three significant figures and include the appropriate units. relative to the shore)

Astudent creates a model of a closed ecosystem by filling a glass tank half full with water, then adding 10 snails and two small aquatic plants. the next day, all the snails are dead. what is the most likely cause of their death?

What is the increase in density of a medium due to wave travel?