I would say B.
A, umm, don't crash trains, that's bad.
C, Lillian is wondering how fast a train can go, not at what curve will it fall.
D, Lillian isn't wondering about the size of the trains, just the speed.
I am most likely sure that it is true
Scientist rely on <em>Biology </em>concepts when researching crop production and medicine.
B - The environment within the cell is stable.
Homeostasis is when your body works to maintain equilibrium (balance) so within a cell, the cell would be stable
