Single stage two envelope system是什么意思不仅是字面意思这应该是一个合同用语，具体怎么理解？

Single stage two envelope system是什么意思不仅是字面意思这应该是一个合同用语，具体怎么理解？ two-stage fuzzy aggregator two-stage runner, two-stage selection是什么意思 【求翻译】Two-stage OLS Regression是什么意思? 麻烦高手翻译几句话：英翻中Pump: Two-stage rotary vane pump with integral single-phase motor. Time to Reach Vacuum Level of: 100 millitorr – 60 Seconds Typical. 50 millitorr – 6 Minutes Typical. Ultimate Vacuum Level: 英语翻译原文：Process of MeiosisUnlike the single-cell division of mitosis,meiosis involves two cellular divisions:meiosis I and meiosis II.Each stage of meiosis runs through the same five stages as discussed in mitosis.During the first round 如何翻译Two stage,two pass Tubular precipitators stage stage two 16-bit single-cycle throughput open env file fail single single single Love is composed of a single soul inhabiting two bodies. Are there two free single rooms?这句话对吗? OK.I want to book 10 standard rooms with two single beds and one room with one single bed.