阅读下列短文，从每题所给的A、B、C、D四个选项中选出最佳选项。
A
A language corpus(语料库)is a huge collection of texts taken from print、video,audioand other sources.It is a powerful tool that can help you learn more about English words andphrases.
The Corpus of Contemporary American English,or COCA,contains over one billionwords from 1990 to 2019.And it has many ways to help learners find out more about howwords are used.
How to use COCA
First,you will need to register with COCA to use the collection.You can register for twokinds of accounts.A free account limits you to 20 searches for words within any 24-hourperiod. A paid account will give you 200 searches within any 24-hour period.
Here are the steps for using COCA to find examples of how a word is used.We vill usethe word profound to show this.
·On the home page.type the word profound in the white search box on the left side ofthe screen.
·Click "find matching strings"just below the search box.This will take you to a newweb-page.
·On this new page.you will see the word profound in blue.Click on it.
·You will now see a page with 100 examples using the word profound,and the wordprofound is shown in green.The source of each example is shown on the left side.
·If you click on the source on the left,COCA will show you a larger part of the textcontaining the example.
·If you want to see more examples,click the two forward page arrows >>at the top orbottom left.This brings you to the next 100 examples.In this way,you might find morekinds of sources for the examples.
21.What is COCA?
A.A textbook on American English changes.
B.A report about the development of English.
C.An Essential tool for beginners of English.
D.A database of Contemporary American English.
22.What is the disadvantage of a free account?
A.Only 200 searches available.
B.Less usage within 24 hours.
C.Only 20 examples per word.
D.Difficulty in applying for an account.
23.How can you find a broader source for each example?
A.Reenter this word on the home page.
B.Click another page with 100 more examples.
C.Click on the left side of the relevant example.
D.Click page arrows at the top or bottom left.
