The collision theory<span> is based on the assumption that for a reaction to occur it is necessary for the reacting species atoms or molecules to come together or </span>collide<span> with one another.\</span>
When the sun is above the horizon and when the sun is below the horizon it is winter
I am sorry I can only answer 7 for you.
Hope it helps
7= By replacing the neurons lost from a injury with new cells.
