A test and pressure relief valve should be installed to assure relief of internal pressure prior to servicing and as a visual indication of trap operation.
应该安装一个测试和压力安全阀，确保内部压力能够在维修前得到释放，并作为疏水阀工作的直观显示。
2
Apart from our waking visions, our internal perceptions can trap us into not accepting reality.
当我们不清醒的时候，我们内心的幻想就会使我们不愿意接受现实。
3
This paper endeavors to use the internal cause of the "Keynesian trap" to explain the partial loss of efficacy in the Keynesian policy in China.