未知题型 实际气体经节流膨胀之后温度都降低。

单项选择题 工程出现质量缺陷，施工单位应根据实体情况及检测结果，及时提出技术处理方案，由（）认可。

单项选择题 The theory has been championed for a number of reasons, but many current proponents point to the presence of methane on comets, meteors, and other lifeless planets as evidence that organic material is not needed to produce. A、envisionedB、demonstratedC、complementedD、advocated