when water freezes, it expands, and has no room to expand in the rock's cracks.
(water; freezes; ) (it; expands; T:when water freezes) (it; has; no room to expand in the rock's cracks; T:when water freezes)
water it it
freezes expands has
T:when water freezes
no room to expand in the rock's cracks T:when water freezes