参考答案：D

解析：

[听力原文]1-4 We all find that learning English takes effort and dedication. There are times when you seem to hit a plateau in learning. A plateau here refers to a flat spot, during which you don’t feel any advancement taking place. Educational research reveals this is normal. But don’t give up. Keep on studying and practicing, and you will soon feel as if you are progressing once again. Just tell yourself that it’s a temporary condition. Meanwhile, study faithfully, do your best, and the rewards will be worth the struggle.

Why do we learn English Most people say that English now becomes an international language, and it is a very useful tool, a means to achieve something else. But specifically, what is the use of a foreign language We may use it to communicate freely with a native speaker. We may use it to get a job with a decent pay. We may use it to help negotiate a business contract with a foreign company. In any case, when you hurry through the last lesson of the language course, you’ll have your completion certificate hanging on your wall. A certificate may mean nothing in comparison with your accomplishment. What is really significant is that you’ have learnt to use that language to your advantage and benefit. A certificate may get stained, lost or be destroyed in a fire, but what’s in your memory will go with you wherever you go. A language skill is worth money in today’s international business world. So study well and cash in on success !