WHAT IS THE PASSAGE MAINLY ABOUT

4. - TUYEN TAP DE THI ANH VAN 11 CO DAP AN HOC KY II 45 PHUT LOP
TUYEN TAP DE THI ANH VAN 11 CO DAP AN HOC KY II 45 PHUT LOP
4. What is the passage mainly about? A. The future of electric power stations B. The advantages of hydroelectric power stations C. The number of electric power stations D. The countries that have nuclear power stations