【正确答案】正确答案： Teaching Assistants A teaching assistant usually works about twenty hours each week. / Teaching assistants are paid to help professors teach students in entry-level study programs. / Generally, the professor gives a talk, or lecture, / to a large group of students one or two times a week. / The teaching assistant meets with smaller groups of students during the week. / The T.A. gives tests and reads any homework or reports the students may be required to write. / Teaching assistants also meet with students who seek help. / They attend teaching meetings. / And some working with science professors help to organize laboratory equipment. /