contact face的用法和樣例：
例句
- Slowly pull the assembly outward to open check allowing exposure of the seat and clapper contact area for cleaning.
慢慢將止回閥往外拉，打開止回閥，使得閥座和閥瓣接觸面暴露出來便於清洗。 - We have seen oil reinvasion above this contact,water reinvasion below,or no reinvasion at all.
我們能看到油的二次侵入在接觸面的上部，水的二次侵入在接觸面的下部或者是根本沒有。
