Fill in each numbered blank with one suitable word or phrase. In American high schools, students move from one class to (Question 41) ____ and study each subject with a different teacher and a different group of classmates. Many high schools have a tracking system, (Question 42) ___ groups students according (Question 43) ___ academic ability and motivation. (Question 44) ____, more capable and hard-working students take more difficult courses. (Question 45) _____ on the subject. classes may be offered at two, three, or even four different ability levels. High school students have (Question 46) ____ very busy day. They have to take five or six academic subjects (Question 47) ____ physical education. They also have to do homework. (Question 48) _____ research in the school library, and take part in activities such as the school band, school newspaper, athletics, drama or clubs. However, these school activities are worth (Question 49) ____ because they help students find friends with similar interests, develop their talents, gain (Question 50) _____ self-confidence, and even discover their career goals. Question 41: