关于第二个例子.我还有疑问:根据句意，第一个and不应该改成or吗？

saved,breaks为何不是被动

.？太简单了吗.以至于 无人问津？

@Foofs Could you do me a favor?

Ok so in "The Gift of the Magi"
Della is saving money: "Pennies saved one and two at a time"
问题是为什么用and而不用or
其实，and或or都是正确的。就是有稍微不一样的意思。但是最后他们两个都能用而且都是正确的。
"Pennies saved one or two at a time" 就会有点条件句的感觉。听上去有点怪应为这个句子是过去时。The author implies that Della is poor and has saved money by bulldozing sellers.
所以用and,: ""Pennies saved(past tense) one and two at a time" 作者是在确认Della是按一硬币和二硬币省的钱。

Pennies saved one and two at a time by bulldozing the grocer... 变成被动时
The Pennies were saved one and two at a time by Della by bulldozing the grocer and the vegetable man and the butcher until one's cheeks burned with the silent imputation of parsimony that such close dealing implied.
这样写的话，句子太长，太乱。用不着。

If my armor breaks,I'll fuse it back together.
如果把他变成被动：
My armor will be fused back together by me if it breaks.
The subject (my armor) is acted on by the verb (fuse) by someone/something (me). This is the passive tense.
那个”by me"就太尴尬了。句子又长又乱。这个句子表达的意思杂乱无章。所以我们就简单地说：“If my armor breaks,I'll fuse it back together.”
Simple, efficient, and easily understandable.