Questions 17 to 20 are based on the following passage. At the end of the passage, you will be given 20 seconds to answer the questions.
Now listen to the passage. What best describes the first English dictionary.
A．It defined easy words as well as hard ones. B．It was nothing more than a list of difficult words. C．It presented good sentences to show how each word was actually used in speech and in writing. D．It was the greatest improvement in the quality of dictionaries.