Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 26 to 30.

      A new lake, (26)__________ has been discovered inside the pristine Thung Cave within the World’s Natural Heritage Phong Nha-Ke Bang National Park in Quang Binh province. The lake is located around one kilometre from the entrance of the cave, in one of the most pristine caverns in the area, situated deep within a strictly protected zone of the national park. It was found in an area about 15 metres higher than the main underground river branch inside the cave,(27) ___________ it look like it was 'floating' on the cave wall. The lake is surrounded by stalactite columns with an underground river system underneath it. The newly-discovered lake has a transparent emerald green colour and has been tentatively named Lo Lung (floating) lake due to its unique location. The source of water flowing into the lake has not yet been determined, with the exploration team also discovering a passage along the cave wall of Thung Cave that traverses the main underground river branch. According to Dung, the team members were unable to determine the lake's water source due to a lack of the necessary depth-sensing equipment.(28)___________, plan on returning for further surveys and explorations in the area in the near future, he added. The Phong Nha – Ke Bang National Park, which covers over 123,000ha, is home to (29)___________  terrestrial and aquatic habitats, primary and secondary forests, sites of natural (30)__________ and tropical dense forests. It is also rich in large, often spectacular and scientifically significant caves, including Son Doong - the world's largest cave.

A new lake, (26)__________ has been discovered inside the pristine Thung Cave within the World’s Natural Heritage Phong Nha-Ke Bang National Park in Quang Binh province.