Located in central Africa, Lake Victoria is a very unusual lake. __( 116 )__ 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, __( 117 )__ more than two million years old. Yet judging by the variety of life in it, Lake Victoria __( 118 )__ a much older body of water. Usually, lakes need a much longer time __( 119 )__ 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 __( 120 )__ 500 different species of just this one type of fish.

(From: <https://www.ets.org/toefl_junior/prepare/standard_sample_questions/language_form_and_meaning>)

__( 116 )__ of the largest lakes in the world; it is also one of the youngest.