Whereas clause, the structure of valve had been improved, holding valve and over load valve had been added in it. The problem had been resolved by means of above.

基于以上现象，对控制支腿缸的换向阀结构进行了改进，通过在原有换向阀的基础上增加一过载阀及4个单向阀解决了上述问题。

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The FPA clause does not cover partial loss of the nature of particular average, whereas the WPA clause over such losses when they exceed a prearranged prearranged percentage.

平安险条款不包括单独海损性质的部分损失，而水债险条款当超过事先商定的百分比时，则包括此类损失。

youdao

"That" defines something, whereas "which" adds new information in a separate clause, often needing commas.

BBC: 10 questions on grammar