What is a serious problem of Lake Baikal in Russia...

Câu hỏi: What is a serious problem of Lake Baikal in Russia?

A. It contains a rich variety of animals and plants.

B. It is polluted by massive volumes of industrial wastes discharged into it.

C. It has 1,300 rare species that do not exist anywhere else in the world.

D. The government did not have the power to enforce laws and regulations.