promised could be done.是什么意思?原句是..That is just what a famous book from the 1930s promised could be done.

promised could be done.是什么意思?原句是..That is just what a famous book from the 1930s promised could be done.
promised could be done.是什么意思?原句是..
That is just what a famous book from the 1930s promised could be done.

promised could be done.是什么意思?原句是..That is just what a famous book from the 1930s promised could be done.
这里从句子结构上来分析,a famous book from the 1930 promise是修饰 what 的.what a famous book from the 1930 promise 就是个主语从句.如同what he said .what he promised .这里的a famous book from the 1930是一个长短语,作用同 he .同理,what he promised could be done .换成陈述句就是he promised sth could be done .中文便是他承诺某些事可以做（完成）.what提前整句意思便是他承诺可以完成的那些事.前面加 that is just .what he promised could be done .整句意思就是那就是他承诺可以完成的那些事
把he 换成a famous book from the 1930.整句意思就是那就是这本很有名的来自1930年书告诉（认定,阐述） 可以完成的事.言下之意,这本书当时肯定分析了一些东西,认为在那个时代可以完成的一些事.那我们现在看到这本书,就知道那就是当年这书（1930）认为（承诺）可以做成的事
这里promise ,could二个动词放在一起易混淆汉语思维.
原句就是a famous book from 1930 promised sth could be done .这里用what替代 sth作主语从句.然后把what这个主句从句作为 that is just的宾语.