67. Dr. Merzenich’s training method mainly depends on ________. (A) speech training (B) computer languages (C) the activities one joins in (D) the information being dealt with

70. Which of the following agrees with the writer's idea? (A) The training methods work better for the old. (B) People should use the brain to stop it from ageing. (C) The training of the brain should start at an early age. (D) It's necessary to take part in as many activities as possible.