请大家帮我看一下第4题的选项为什么是C,而其他为什么不可以呢?

请大家帮我看一下第4题的选项为什么是C,而其他为什么不可以呢?
In order to know a foreign language thoroughly,four things are necessary.Firstly we
must be able to understand the language when we hear it spoken.Secondly,we must be able to
speak it ourselves correctly,with confidence and without hesitation.Thirdly,we must be able
to read the language and fourthly,we must be able to make sentences that are grammatically
correct.We must know how to arrange sentences in paragraphs,so as to write a good letter or
composition.
There is no easy way to success in language learning.A good memory is a great help,but
it is not enough simply to memorize rules from a grammar book.It is not much use learning by
heart long lists of words and their meanings.We must learn words not by themselves,but in
sentences.We must learn by using the language.“Learn through use” is a good piece of
advice for those who are studying a new language.Practice is very important.We must practise
speaking and writing the language whenever we can.
1.The word “confidence” here probably means “( )”.
　　A.use B.eyes C.need D.no question
2.The writer advises us to ( ).
　　A.speak more and write more B.read more
　　C.speak more D.use a dictionary
3.The first step in learning a language is ( ).
　　A.reading B.speaking C.writing D.listening
4.Words should be learned in a( ).
　　A.dictionary B.textbook
　　C.sentence D.good grammar book
5.“Learn through use” is to say that we must( ).
　　A.practice speaking and writing
　　B.learn by using the language
　　C.learn everything by heart
　　D.remember grammar rules as many as possible

前面那两句：It is not enough simply to memorize rules from a grammar book.排出了D.
It is not much use learning by heart long lists of words and their meanings.长列的单词和词意代表了字典,排除A
至于B是课本的意思,文中没有提及.事实上这篇文章侧重于英语的应用We must learn by using the language,而照着课本是最死搬硬套的,所以这个选项不可能
We must learn words not by themselves,but in sentences.这是原文,选C.
不知道你对我的解释有没有意见