Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase for each of the blanks.  

            Located in central Africa, Lake Victoria is a very unusual lake. __( 44 )__ of the largest lakes in the world; it is also one of the youngest. Estimated to be about 15,000 years old, it is a relative baby compared with Earth’s other very large lakes, __( 45 )__ more than two million years old. Yet judging by the variety of life in it, Lake Victoria __( 46 )__ a much older body of water. Usually, lakes need a much longer time __( 47 )__ by a diverse array of life-forms. It is common for new lakes to contain only a small number of species. Lake Victoria, however, is packed with colorful fish, most notably, cichlids. There are __( 48 )__ 500 different species of just this one type of fish.

Question: 46