(1) The older you get, the more difficult you learn English.
→ the more difficult it becomes (for you) to learn
(2) A lot of people believe that the more books they read, the more they become knowledgeable.
→ the more knowledgeable they become
(3) The more I thought about the project, the more I did not like it.
→ less liked
(4) That question was easy than I had expected. → easier
(5) Our new house has rooms twice as many as the one where we used to live.
→ twice as many rooms as
（解答）The math test was not was difficult as I (had) expected.
（別解） The math exam turned out to be easier than I (had) expected it to be.
・聞き手との共通認識と考えtheをつける。よって、the math test [exam]が適切。
the test in mathという言い方もある。
・「未来において～になるだろうと思っていた」の意味、expectを使うのが適切。thinkだと未来の内容だと限らないので I had thought it would be と補ったほうが明確に意味を出せる。
・「思った」は「難しくなかった」よりも前なので、大過去にするのが原則だが、自明なので過去形でも可。またthan it was expected からit was が脱落した than expected という形でも可。
・not as difficult [hard] as ～ / easier than ～ が適切。less difficult [hard] than ～ は文法的には可。口語的ではない。
・「～なかった」は、「結果として～だと判明した」という気持ちを表すなら turned out to be ～ / proved to be ～ とする。
（解答） Statistics show that the population of China is about ten times as large as that of Japan.
（別解） According to (the) statistics, the population of China is about ten times larger than that of Japan.
（解答） The more I read Natalie's letter, the less I understood her intention.
（別解） The more times I read her letter, the less I could understand what Natalie meant.
（解答） The older you get, the more quickly you feel (that) time passes.
（別解） The more you age, the faster time seems to pass.
（解答） The more we know about the past, the more we realize how important it is to learn from it.
（別解） The more we know about the past, the more we realize that it is very important to learn from it.
（解答） Japanese students watch TV twice as long as students in other developed countries. However, they spend less than half as much time reading.
（別解） Students in Japan spend twice as much time watching TV as students in any other developed country. In addition, they read less than half as much.
（解答） The more thought about the problem, the more difficult it seemed to me. Finally, I gave up trying to solve it.
（別解） The longer I thought about the question, the more difficult I found it. Finally, I gave up trying to answer it.
（解答） When you want to learn a foreign language, the earlier you bigin to
study (it), the faster you make progress in the language.
（別解） If you try ti learn other languages, the younger you are when you start, the more rapidly you improve.
（解答） Last winter, I took a long vacation and went to Los Angeles. However, it was not as warm as I (had) expected.
（別解） Last winter, when I took a long vacation, I visited Los Angeles. The city was not as warm as I (had) expected it to be.
（解答） It is said (that) those who are talking on the mobile phone while driving are about four times as likely to cause a trafic accident as those who are concentrating on driving.
（別解） People say that if you are talking on the mobile phone while at the wheel, you are about four times as likely to have a trafic accident as (you are) when you are concentrating on driving.
This graph shows us the percentage of children in three age groups who owned mobile phones in 2005 and 2009. The number increased in all three age groupd. The older the children were, the more likely it was that they owned a mobile phone and the greater the increase in the proportion of owners between 2005 and 2009.