HELPhelp ASAP)If a substance has a half-life of 45 days, how much of the original substance would be left after 90 days?
A. One half (1/2)
B. One quarter (1/4)
C. One eighth (1/8)
D. One tenth (1/10)

Biology 1c cumulative exam i need awsners

!if we removed the wolf, snake, and hawk from this food web, what best explains the impact it would have? a) the number of producers would increase. b)the number of decomposers would increase. c)the number of primary consumers would increase. d)the numbers of primary consumers would decrease.

What causes the force that pushes magma from the magma chamber through the pipe and vent of a volcano?