Read the following passage and mark the letter A, B, C, or D to indicate the correct answer that best fits each of the numbered blanks.

Lake Baikal is a huge lake in Siberia, Russia. It is the (21) __________ fresh water reservoir in the world. The lake is near Irkutsk.
Lake Baikal is about 636 kilometres long. It is 20 to 80 kilometres wide. (22) __________ its deepest point, it is 1,700 metres deep. With this depth, it is the deepest lake on Earth. The lake is (23) __________ UNESCO World Heritage Site. It holds about 20% of the world's unfrozen surface fresh (24) __________.
The lake has fish that exist only here and nowhere else. It is home to more than 1,700 (25) __________ of plants and animals, two-thirds of which can be found nowhere else in the world.