外语的问题，帮个忙！！！

but a few ……除了一些……这是插在all the graduates....的所以这句子的真主语是all the graduates but a few 是表补充说明的
又如there is nothing but a desk那儿什么也没有（只有一张桌子）

but [简明英汉词典]
[bEt, bQt]
prep.除...以外
conj.而是, 但是
adv.几乎, 仅仅
but [用户词典]
1/bQt, also bEt; bQt, bEt/
adv
---------- 1 ----------

(esp dated or fml 尤作旧或作文雅语) only 只; 仅仅:
* He's but a boy. 他不过是个孩子.
* If I had but known she was ill, I would have visited her. 我倘若知道她病了, 早就去探望她了.
* I don't think we'll succeed. Still, we can but try. 我想我们不会成功. 但是不妨试一试.
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(idm 习语) one cannot/could not but...
(fml 文) one can only...; one is obliged to... 不得不...; 只好...:
* It was a rash thing to do, yet one cannot but admire her courage. 这事做得过於鲁莽, 然而不能不佩服她的勇气.
* I could not but admit that he was right and I was wrong. 我不得不承认他对了, 我错了.

all but a few of 除了一些,大部分都是

but意为“除了”
除了一两个学生，俄亥俄大学所有的学生所作的调查都来自于其他国家。，

All