例句與造句

1. The phenomenon of crack closure , which is important for the crack growth , is widely existed in the progress of fatigue crack growth in the metal materials
   裂紋閉合現(xiàn)象普遍的存在于金屬材料的疲勞裂紋擴展過程中，對裂紋擴展有著重要的作用。
2. It's difficult to find progress of fatigue in a sentence. 用progress of fatigue造句挺難的