1.Bob doesn't know ___ to write about.

A how B that C what D where
2. i can't decide___.
A what to do it B how shall i do it C how to do it D what shall i do it
说明区别 还有 就是什么事用what to do什么时候用 how to do

第一题 也要说明区别哦！

1.Bob doesn't know ___ to write about.
选C.
about 是介词，后面要跟个名词性质的词作宾语。what 就是这样的词。
BOB不知道该写些什么。
如果选how，要添加一个宾语It。所以，句子要变成Bob doesn't know how to write about it.

. i can't decide___.选C。
A what to do it B how shall i do it C how to do it D what shall i do it
what已经是宾语了（这里作动词decide的宾语）所以，如果加个IT。就重复了。
这题用HOW.道理同上题。
另外，宾语从句里得用 陈述句语序。所以B错在顺序。应该是how i shall do it.

第一题选C，第二题选C what to do是表示做什么，后面不能接it,how to do 表示怎么做，后面可以接it的！

C, what 作为write about 的宾语， 若用how的话， 是how to write about it. 同样第二题选C A多了it，B 需要陈述句语序。

bob doesn't know the way to the cinema. i don't know, too.

鲍勃不知道去电影院的路。我也不知道。

what to do how to do it what的短语后面一定不能带it,them之类的词，how的短语后面一定要带名词 所以 1 C 2 C