Answer for brainliest!!

When water freezes, it . contracts expands

The concept of keystone species is controversial among ecologists because most organisms are highly interdependent. if each of the trophic levels is dependant on all others how can we say one is most important

When in solution, a molecule that moves slowly across an artificial membrane moves rapidly across a plasma membrane. this molecule rapidly enters the cell regardless of whether its concentration is higher inside or outside the cell. using this information, which transport mechanism is most likely to be responsible for the movement of the molecule across a plasma membrane? view available hint(s)when in solution, a molecule that moves slowly across an artificial membrane moves rapidly across a plasma membrane. this molecule rapidly enters the cell regardless of whether its concentration is higher inside or outside the cell. using this information, which transport mechanism is most likely to be responsible for the movement of the molecule across a plasma membrane? active transportexocytosis