A、Because it is a tonal language. B、Because its grammar is irregular. C、Because its characters are difficult to remember. D、Beca

I have always believed the real test of language proficiency is its ability to create connections between people. While there are many difficult languages, the hardest language of them all is undoubtedly Chinese.
   It’s not just me voicing my difficulty. The UN officially confirms it. The hardest language to learn, according to the United Nations Educational Scientific and Cultural Organization, is Chinese.
   One of the reasons why Chinese is difficult is that it is a tonal language and it’s the tone that decides its meaning. For instance, the word "mai" means both buy and sell, just changing the tone can make one a buyer or seller! As if the tonal difficulty wasn’t enough, similar sounding words abound in Chinese, and your head will swim trying to remember the vocabulary. Oh, did I mention "hanzi"—Chinese characters?
   Difficulties aside, there are countless benefits. If you are brave like me, it’s a wild rollercoaster ride that is worth a try.
   The trick is to get a good teacher who excels in Chinese but also knows English fairly well so that your queries and concerns can be adequately addressed.
   Learn from everyone and eveiything. I learned a lot by listening to housekeeping staff, cashiers, hairdressers and the like. Eveiything can teach you, provided you are "present. "
   Keep targets in mind and work hard to meet them. Review your progress in due course so that you can know whether you are steadily sailing further.
   Switch to Chinese. Instead of finding locals who speak English, however comforting it may be, embrace Chinese and use it everywhere. Soon you will know the subtle differences in the usage of the language.
Questions 9 to 11 are based on the passage you have just heard.
9. Why is Chinese difficult to learn?
10. What is the trick of learning Chinese well?
11. What can Chinese learners do to find the delicate differences of the language?