单项选择题
A．Social work. B．Medical care. C．Applied physics. D．Special education.
A．How animals survive harsh conditions in the wild. B．How animals alter colors to match their surroundings. C．How animals protect themselves against predators. D．How animals learn to disguise themselves effictively.
A．At a country school in Mexico. B．In a mountain valley of Spain. C．At a small American college. D．In a small village in Chile.