n.在Z形路轨向原来的方向返驶，改变角度( switchback的名词复数 )...

switchbacks的音标：...

The Grand Challenge race would be 142 miles of perilous mountain switchbacks and rough, sandy trails.大挑战赛车会有228公里危险的蜿蜒山路,以及崎岖不平又多沙的路面....