单项选择题Users of plagiarism detection tools make a point of using the service secretly because ______.
单项选择题The number of specialists has enormously increased mainly because of ______.
单项选择题It is suggested in Para. 2 that ______.
单项选择题Which of the following is NOT true according to the passage
单项选择题According to the passage, plagiarism remains a growing problem largely because ______.