During their journey they came upon many sand dunes piled up by the winds.
During their journey they came upon many sand dunes piled up by the winds.
他们在路上看到许多被风吹积而成的沙丘。
During their journey they came upon many sand dunes piled up by the winds.
他们在路上看到许多被风吹积而成的沙丘。