They did not find ?____? to prepare for the worst conditions they might meet.

首先，worthy确实可接不定式to和介词of，但要注意，其搭配为“be”worthy to及“be”worthy of

题中的it为形式宾语，真正宾语为不定式短语to prepare for the worst conditions they might meet，worthwhile为补语。

若要用worthy，那么应表达为：
They did not find it a worthy thing to prepare for the worst conditions they might meet.
此时a worthy thing 做补语。

通常worthy是跟of的

worthy of...

B. it worthwhile为正确表达
worthwhile是“值得的”，“有价值的”
?
worthy虽也是形容词，但常含贬义。且常与of连用，be worthy of。。。

He said he was not worthy to accept such honour 注意这句话的主语是he，不是it，再有 he 与 accept 是主动的关系，所以可以。但本题中，用worthy的话，应该是 it worthy of being prepared 或 it worthy to be prepared 才对。另外 worthy后面跟to do 不常见

三个词区别：

1.worth adj&n.值得，应该,作形容词在句中只能作表语
①sb./sth. be worth ... :
His words are worth notice.他的话值得注意.
The bike is worth 200 yuan.
②be (well) worth doing (很)值得做...,注意这个句型是主动表被动的用法,如这本书值得一读
This book is worth reading.
2.worthy adj&n.有价值的,值得...的,做形容词时既可以做表语又可以作定语
①be worthy