17. As college tuition has climbed, so has the number of students who borrow to help pay  for them. (A)tuition (B) has(C)who(D)them

27. According to the passage, which of the following is NOT a characteristic of austral summer? (A) It is the best time for animals to produce offspring. (B) Researchers don’t like to stay at this time of year. (C) One doesn’t see the moon. (D) It happens in the South Pole.