帮忙翻一下吧 几个术语

let me try:
methyl siloxane 甲基硅氧烷

portions water (根据前后文翻译)

graduate, stopper刻度的,塞子

graduated cylinders (graduates), glass-stoppered (g-s), 100 mL, and plain,250 mL具玻璃塞的100ml刻度量筒和250ml普通量筒(不知你这是不是一个句子,只好根据感觉翻译了)

Kuderna-Danish concentrator (K-D), 500 mL, with Snyder column, graduated or plain receiving flask500ml的带有斯耐德柱的K-D浓缩器,具刻度或普通的收集瓶(snyder column?)

you'd better upload the phrase here, translation is always based on the sentence, not a single word

这些baidu一下就能找到了。