单项选择题
A．Dangerous Sports--What and Why B．The Boredom of Modem Life C．Bungee Jumping--Is It Really Dangerous D．The Need for Excitement
A．jump as high as you can B．slide down a rope to the ground C．attach yourself to a rope and fall to the ground D．fall towards the ground without a rope
A．One kind of animals is eaten up. B．One kind of plants is destroyed. C．One kind of animals eats another. D．One of the links is destroyed.