英式：[seɪf]美式：[saɪf]
赛夫沙丘(顺着风向的长沙丘)
Longitudinal or seif dunes are dunes that are parallel to a strong wind that blows in one general direction. 纵向或者赛夫沙丘是与强风平行的沙丘，风总是以相同方向刮过。