LOUIS IS VIRTUALLY BILINGUAL--- DUTCH AND GERMAN.A. ON B. IN C. FO...

22. Louis is virtually bilingual--- Dutch and German.A. on B. in C. for D. with.. Read the passage and choose the correct answer to each of the questions. Son Doong Cave has become more famous after the American Broadcasting Company(ABC) aired a live programme featuring its magnificence on ‘Good Morning America’ inMay 2015. Located in Quang Binh Province, Son Doong Cave was discovered by a local man namedHo Khanh in 1991, and became known internationally in 2009 thanks to British cavers,led by Howard Limbert. The cave was formed about 2 to 5 million years ago by riverwater eroding away the limestone underneath the mountain. It contains some of the tallestknown stalagmites in the world - up to 70 metres tall. The cave is more than 200 metreswide, 150 metres high, and nearly 9 kilometres long, with caverns big enough to fit anentire street inside them. Son Doong Cave is recognised as the largest cave in the worldby BCRA (British Cave Research Association) and selected as one of the most beautifulon earth by the BBC (British Broadcasting Corporation).In August 2013, the first tourist group explored the cave on a guided tour. Permits arenow required to access the cave and are made available on a limited basis. Only 500permits were issued for the 2015 season, which runs from February to August. AfterAugust, heavy rains cause river levels to rise and make the cave largely inaccessible.