单项选择题
A．are trying activities such as bungee jumping B．are climbing the highest mountains C．are coming chose to death in sports D．are looking for adventures such as exploring unknown
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．they have a lot of free time B．they can go to hospital if they are injured C．their lives lack excitement D．they no longer need to hunt for food