Because of the cruelty involved,scientists could never carry out this test on humans.由于這種做法的殘忍性，科學家永遠不會在人類身上做這樣的實驗

because of因為； 由于

She could only croak because of her heavy cold.

她因患重感冒只能用沙啞的聲音說話。

The war was lost because of a shortage of munitions.

戰爭因軍火不足而失敗。

The best scientists could hope for would be to find real live case studies,科學家能期望的頂多是找到這樣的實例來研究

hope for希望； 期待

We all hope for an improvement in the weather.

我們都希望天氣好轉。

We hope for some gain from our investment.

我們希望投資有利可圖。

feral children, those brought up by animals in the wild.比如在野生環境下由動物撫養長大的孩子

bring up教育；養育

The couple contrived to bring up their children on a small income.

這對夫妻設法以菲薄的收入把孩子扶養成人。

The lamb had to be brought up by hand.

這只小羊要用奶瓶喂養。