alternation of direction

• 换向

alternation of direction的用法和样例：

例句

1. A new type of digital directional valve is presented.
   给出了一种新型电液数字换向阀。
2. Study on the moisture uniformity of paddy drying technology by employing air direction reversals.
   稻谷换向通风干燥不均匀度的试验研究。