Read the following passage and mark the letter A, B, C, or D to indicate the correct answer to each of the questions.

It is often considered that the schoolyard is where bullies go to make other kids a miserable school life, but a new study suggests that classrooms are another popular place.The study, presented recently at the American Public Health Association's yearly meeting in Philadelphia, is based on the results of the research from more than 10, 000 middle school students who answered questions online.

Of those researched, 43% said they'd been physically bullied within the last month.A bit more than half said they had been laughed at in an unfriendly way, and half reported being called hurtful names.About one third said groups had excluded them to hurt their feelings.28% said their belongings had been taken or broken; 21% said someone had threatened to hurt them.According to the results, two-thirds of the students said they had been bullied in more than one way over the previous month.

The study authors mentioned that 8% of the students who answered said they had missed school at least once during the school year because of fear of being bullied.25% said they had taken other actions, such as missing recess, not going to the bathroom or lunch, missing classes, or staying away from some area of the school to escape from experiencing a bully.Bullies did too much to the school life.

Mark the letter A, B, C, or D to indicate the word that differs from the A. external B. determine