Poor show in Pisa rankings

IN a lower secondary level Science question, students are asked to explain what happens when the muscles are exercised. Two options are given as answers — muscles get an increased flow of blood or fats are formed in the muscles. (The correct answer: muscles get an increased flow of blood.)

Compare that to a question asked in the Programme for International Student Assessment (Pisa): Why do you have to breathe more heavily when you are doing physical exercise than when your body is resting?