Choose the options that best complete the passage.

Sơn Đoòng Cave

 

Sơn Đoòng Cave is (36)___________ at the heart of Phong Nha Kẻ Bàng National Park in Quảng Bình Province. It was originally discovered in 1990 by a local man named Hồ Khanh while he (37)___________ for timber. When he peered inside the opening of the cave, he saw clouds and heard the sounds of a river. (38)___________, he didn’t dare to go any further. The cave stayed unknown to the rest of the world until Hồ Khanh found its entrance again in 2008. Later, he (39)___________ the way for a British expedition to explore it. In 2010, it was officially announced that Sơn Đoòng was (40)___________ largest natural cave in the world, (41)___________ to house an entire New York City block. The cave is home (42)___________ rare fauna that can (43)___________ be found anywhere else. (44)___________ fossils were also found in the cave. As tours to Sơn Đoòng gain in (45)___________, hopefully the unique natural system will still unchanged.

Sơn Đoòng Cave is (36)___________ at the heart of Phong Nha Kẻ Bàng National Park in Quảng Bình Province.