3. An awareness that they were being experimented upon seemed to be enough to alter workers's behavior by itself.

【分析】復合句。句子主干為 。An awareness...seemed to be enough to alter...。 that 引導同位語從句補充說明 awareness， 其中 they 指代后面的 workers。be enough to do “足以...”。

【譯文】只要意識到她們在接受實驗，這一意識本身似乎就足以改變工人們的行為。

4. Contrary to the description on record, no systematic evidence was found that levels of productivity were related to changes in lighting.

【分析】復合句。句子主干為 no systematic evidence was found...。 Contrary to 作句子狀語，that 引導的從句作 evidence 的同位語，為避免句子頭重腳輕，此同位語從句與先行詞被謂語分離。

【譯文】與有記載的描述相反，沒有找到系統的證據來說明勞動生產率的水平與光照的變化有關。