什么叫喷嘴弧？
参考答案：
采用喷嘴调节配汽方式的汽轮机第一级喷嘴，通常根据调节汽门的个数成组布置，这些成组布置的喷嘴称为喷嘴弧段，简称喷嘴弧。
无菌过滤流程：待滤啤酒→（）→PVPP过滤机→（）→膜过滤→缓冲罐→（）
Having walked in the desert for several days, we felt exhausted, but we had to find a pool before water in the bottle ____.
A．ran out of
B．ran away
C．ran out
D．ran off
