WHAT DOES “THEY” IN THE SECOND SENTENCE OF THE LAST PARAGRAPH REFER...

5. - 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
5. What does “they” in the second sentence of the last paragraph refer to? A. Hydroelectric power stations B. Coal power stations C. Nuclear power stations D. Gas power stationsPick out the word whose underlined part is pronounced differently from that of the others: