【T17】 A.THE HIGHEST MOUNTAINS B.AS BUNGEE JUMPING C.BE CURED D.TO SEEK DANGER A.DISEASES COULD NOT EASILY【T13】______, AND LIFE WAS A CONTINUOUS BATTLE FOR SURVIVAL B.MOST PEOPLE WOULD SAY ARE AS RISKY【T14】______INVOLVE JUMPING C.THE ANSWER FOR SOME OF THESE PEOPLE IS【T15】______IN ACTIVITIES D.THOSE WHO HAVE CLIMBED【T16】______, EXPLORED UNKNOWN PARTS OF THE WORLD OR SAILED IN SMALL BOATS AROUND THE WORLD MORE AND MORE PEOPLE ARE TAKING PART IN DANGEROUS SPORTS AND ACTIVITIES.OF COURSE, THERE HAVE ALWAYS BEEN PEOPLE WHO HAVE LOOKED FOR ADVENTURE—【T17】______ACROSS THE GREATEST OCEANS.NOW, HOWEVER, THERE ARE PEOPLE WHO SEEK ANIMMEDIATE EXCITEMENT FROM A RISKY ACTIVITY WHICH MAY ONLY LAST A FEW MINUTES OR EVEN SECONDS. I WOULD CONSIDER BUNGEE JUMPING TO BE A GOOD EXAMPLE OF SUCH AN ACTIVITY.YOU JUMP FROM A HIGH PLACE (PERHAPS A BRIDGE OR A HOT-AIR BALLOON) 200 METERS ABOVE THE GROUND WITH AN ELASTIC ROPE TIED TO YOUR ANKLES.YOU FALL AT UP TO 150 KILOMETERS AN HOUR UNTIL THE ROPE STOPS YOU FROM HITTING THE GROUN D.IT IS ESTIMATED THAT TWO MILLION PEOPLE AROUND THE WORLDHAVE NOW TRIED BUNGEE JUMPIN G.OTHER ACTIVITIES WHICH【T18】______FROM TALL BUILDINGSAND DIVING INTO THE SEA FROM THE TOP OF HIGH CLIFFS. WHY DO PEOPLE TAKE PART IN SUCH ACTIVITIES AS THESE? SOME PSYCHOLOGISTS SUGGEST THAT IT IS BECAUSE LIFE IN MODERN SOCIETIES HAS BECOME SAFE AND BORIN G.NOT VERY LONG AGO, PEOPLE'S LIVES WERE CONSTANTLY UNDER THREAT.THEY HAD TO GO OUT AND HUNT FOR FOOD,【T19】______. NOWADAYS, ACCORDING TO MANY PEOPLE, LIFE OFFERS LITTLE EXCITEMENT.THEY LIVE AND WORK IN COMPARATIVELY SAFE ENVIRONMENT; THEY BUY FOOD IN SHOPS; AND THERE ARE DOCTORS AND HOSPITALS TO LOOK AFTER THEM IF THEY BECOME ILL.【T20】______SUCH AS BUNGEE JUMPIN G.