简述减压水封破坏如何处理?
参考答案:
①若破虹吸有问题,迅速处理,保持畅通;
②迅速将水封变成油封;
③迅速处理好放大气管线堵塞或存油冻凝
The foreigners England, but they speak Chinese very well.
A.come in
B.come out
C.come from
D.come back
单孔类(如鸭嘴兽)是()
A.卵生,尚无乳腺
B.卵生,乳腺有假 * *
C.卵生,乳腺无 * *
D.胎生,乳腺有真 * *