Which of the following weathering processes involves the constant freezing and thawing of water?

plz me

1) these are barrel shaped microtubules in most animal cells, that organize the spindles during cell division

Which part of a feedback mechanism is able to monitor the conditions outside of cells and usually uses nerve cells to relay this information to an intergrating center

Anthracite is so hard and pure it is also referred to as a renewable resource metamorphic rock hot bituminous coal dirty fuel