例句與造句

1. This machine is newly researched and designed by our factory based on the model of combined cam , it winds up the plastic tape by the back and forth movement of the swinging stem driven by the cam
   采用心型凸輪的旋轉來帶動擺桿作來回移動而卷繞成形。比原往復絲桿的結構運轉更加輕松
2. It's difficult to find back and forth movement in a sentence. 用back and forth movement造句挺難的