two-stage mass spectrometer

例句：

1. 1. The two-stage processinvolves several steps before the final product isproduced.
   这个两级过程在最终产品产生之前需要经过几个步骤。
2. 2. Thecompany has implemented a two-stage system to improve efficiency.
   该公司已经实施了一个两级系统来提高效率。
3. 3. The two-stage approach helps usunderstand the complex relationships between variables.
   这种两级方法帮助我们理解变量之间的复杂关系。