短语讲解：

1.He told VOA he wanted to prevent communism from spreading.

prevent from 阻止， 防止
例句：Active cure of swoon patients was important to prevent from complications.
积极救治晕厥患者，对预防并发症有重要意义。

2.He added that because of those efforts, communism did not spread.

because of 因为，由于; 基于
例句：It is mainly because of my fault.
这主要是由于我的过错。