The supernatant was collected and concentrated in vacuum to evaporate the solvent.
Concentrate 就是 evaporate the solvent ， 后面的 to evaporate the solvent 是多余的.类似的把一些词的含义再次重复说明是最容易出现的多余用词.类似的 8PM in the evening, blue in color, small in size, in vivo animal models, in vitro cell cultures 都有多余用词的情况 .
The results of activities of tested compounds were listed in Table 1.
Results 是多余的.中文中经常写作“ 实验结果”“ 活性检测结果”，但英文中“ 结果 ”是不需要翻译出来的 .
宜改为： The activities of tested compounds were listed in Table 1.
下面的例句中， their 就是 acid B and D ， 二者要去掉一个 .
The chemical mechanisms of their antioxidant activities of acid B and D were not well understood.
宜改为： The chemical mechanisms of the antioxidant activities of acid B and D were not well understood.
一些词组， 如 it should be mentioned, it should be pointed out, it was found, it was determined, … 都是冗长和委婉地说法，应该直接 说明 .