double direction短语¹⁸⁰⁰⁹⁸⁺¹ 基本例句 双向 According to the theory of single cylindrical helical torsional spring, the cylindrical helical spring in double direction was designed to realize the test of torsion. 利用单个圆柱螺旋扭转弹簧扭转原理，给出了一种用双向扭转圆柱组合螺旋弹簧实现扭矩测试的方法。 cnki