Context: Before glaciation, mountain valleys have a characteristic "V" shape, produced by eroding water. During glaciation, these valleys are widened, deepened, and smoothed, forming a "U"-shaped glacial valley. The erosion that creates glacial valleys eliminates the spurs of earth that extend across mountain valleys, creating triangular cliffs called truncated spurs. Within glacial valleys, depressions created by plucking and abrasion can be filled by lakes, called paternoster lakes. If a glacial valley runs into a large body of water, it forms a fjord.

Question: What shape do mountain valleys have pre-glacation?
Answer: characteristic "V" shape

Question: What gives mountain vallys their characteristic "V" shape before glacation?
Answer: eroding water

Question: How is a fjord formed?
Answer: a glacial valley runs into a large body of water

Question: What shape do glacial valleys have after being widened by glacation?
Answer: "U"-shaped

Question: What has a V shape after a glacier recedes?
Answer: Unanswerable

Question: What are U shaped before glaciation?
Answer: Unanswerable

Question: What fills depressions to form fjord?
Answer: Unanswerable

Question: What do glacial valleys run into to form paternoster lakes?
Answer: Unanswerable