单项选择题
A．are done in a week B．aren't very clear C．are done in 24 hours D．take a long time
A．ask other students to write their papers B．draw pictures instead C．copy from reference books D．copy papers or large parts of papers from the Internet
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