A BALLOON RISES BECAUSE OF THE HOST AIR OR GAS INSIDE THE BALLOON IS...

48: A balloon rises because of the host air or gas inside the balloon is lighter than the air outside.A (because) B C DRead the following passage and mark the letter A, B, C, or D on your answer sheet to indicate thecorrect word for each of the blanksTHE TRADE IN RHINO HORNLast year thieves broke into a Scottish castle and stole only one thing: a rhino horn, at 1.5 meters wasthe longest in the world. In China pharmaceutical (49)_____ have been building up collections ofantiques made from rhino horn, for the sole (50)_____ of smashing them to powder to make the(51)_____ ingredient for many of their medicines. And in Africa poachers continue to die in the(52)_____ for black rhino.Recently, conservationists met to plan a campaign to persuade countries where rhino horn is (53)_____part of the traditional medicine to (54)_____ substitutes. The biggest threat to the survival of therhinoceros is the (55)_____ of certain countries to enforce a ban on domestic trading in rhino horn. The rhino horn is included in many (56)_____ for disorders ranging from fevers to nosebleeds. Horn,like fingernails, is made of keratin and has no proven medicinal (57)_____. Traditional substitutes, suchas horn from buffalo or antelope, are regarded as second best.The battle is thought to be winnable. But it may be harder than the battle against the trade in ivory, forthere is a (58)_____ between the two commodities. Ivory is a luxury; rhino horn, people believe, couldsave the life of their child.