[单项选择]

Passage Two
There Student thieves look out. Students can easily get many research papers off the Internet. A new Web site could help teachers catch copiers.
Some students research and write their term papers. Others, however, just copy them off the Internet and turn them in as their work.
Two graduate students at the University of California at Berkeley have written a program to catch the students who copy. It compares a student’s paper with every other term paper on the Web.
A hundred million Web pages on the Internet are searched. The top 20 search engines are used for the search. This service can be found at www. plagiarism, com. They also have a local data base of term papers.
Teachers who sign up can send their students’ papers to the Web site. Within 24 hours they know if the student did the work.
Every sentence that was a word-for-word match with another sentence either found on the Internet or within our d
A. they ask other teachers to read their students' papers
B. they ask their students to list their sources of information
C. they can sign up for the Internet service
D. they search the Internet and compare papers