two stages

• 两大阶段

two stages的用法和样例：

例句

1. Earth evolution and gold metallization in Jiapigou area are divided into three stages and three kinds of tectonic belts with the help of metallogenic dynamic system theory.
   运用成矿动力系统思想把夹皮沟区地壳演化和金成矿分为三大阶段和三大构造带。