Read the following passage and mark the letter A , B , C , or D on your answer sheet to choose the word or phrase that best fits each of the numbered blanks from 1 to 5 . Phong Nha - Ke Bang ( Phong Nha - Kẻ Bàng ) is a national park in the center of Quang Binh province in north - central Vietnam . It protects one of the world's two largest karst regions with several hundred caves and grottoes . Its name ( 1 )__________ from Phong Nha cave, the most beautiful one, with numerous fascinating rock formations , and Ke Bang forest . The plateau is probably one of the finest and most ( 2 )__________ examples of a complex karst landform in Southeast Asia . Here , there are the charming Son and Chay Rivers , gently flowing in the middle of the two sides ' reed and green bamboo rows . ( 3 )_________ of the caves here have been shaped by those two rivers . The Son River flows into the mouth of the Phong Nha cave , ( 4 )________ is the only point where it emerges in around 20 km . ( 5 )___________ there are more than ten spectacular streams , springs and waterfalls in Phong Nha - Ke Bang area . Question 1 . A. spreads B. distributes C. derives D. supports Question 2 . A. distinctive B. impressed C. threatening D. worrying Question 3 . A. Much B. Each C. Almost D. Most Question 4 .A. where B. that C. it D. which Question 5 . A. However B. Thus C. For example D. Also