Which is a nonliving factor that defines a spruce-fir forest ecosystem?
A) type of soil
B) type of trees
C) type of bacteria
D) type of mammals

Atank contains 240 liters of fluid in which 10 grams of salt is dissolved. brine containing 1 gram of salt per liter is then pumped into the tank at a rate of 6 l/min; the well-mixed solution is pumped out at the same rate. find the number a(t) of grams of salt in the tank at time t.

Determine the percent sulfuric acid by mass of a 1.61 m aqueous solution of h2so4. %

What happened in 2012 and how does it illustrate the importance of understanding the sun and how it works?