VOA慢速英语:Bess Lomax Hawes, 88, Brought Folk Music to a Wider Public

1.In the nineteen forties, after college, Bess Lomax joined the Almanac Singers, a group that sang social protest songs.

a group是Almanac Singers的同位语，that引导定语从句，修饰a group。

2.He worked with her and remembers how she worked to keep folk traditions from being lost.

prevent...from,keep...from还有stop……from 这三个句式的意义都是：阻止……做……或阻止某事的发生，而protect...from是表示保护……不受伤害

prevent...from 和stop%from 用在主动语态中from可以省略。
keep...from在表示此意时，from不可以省略。keep……doing 是使……处在……状态中的意思。
prevent...from,keep...from还有stop……from 这三个句式中from后面的动词与from前面的词构成动宾关系时，后面用动名词的被动形式。
We must prevent the water from being polluted.
What stopped him from coming here.
The heavy rain kept us from coming on time.
I am sorry to have kept you waiting.
You had better wear sunglasses to protect your eyes from the sun.

关于keep的其他短语：

keep back阻止,阻挡;隐瞒,保留
keep down控制,压制,镇压;压低,放低(声音)
keep from使...不(做)
keep off不接近,避开
keep on继续不断,保持
keep out of躲开,置身...之外
keep to坚持,保持
keep up保持,维持;继续进行,坚持
keep up with向...看齐,跟上...

3.She and Jacqueline Steiner took old music and wrote new words in support of a Progressive Party candidate for mayor of Boston, Massachusetts.

in support of支持
 
例句：The judge quoted various cases in support of his opinion.
      那位法官引证不同的案例以支持他的意见。

证明…正确

例句：I'll mention some facts in support of my argument.
      我要举出几个事实来证明我的理论。