Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 18 to 22.

In November 2021, world leaders met in Glasgow, in Scotland, for the COP26 summit. (18) ___(1)___. Many countries promised to become "carbon neutral" before 2050. (19) ___(2)___. World leaders agree that we have to stop using coal and oil to generate heat and electricity; we should use green energy sources instead, known as "renewables."
The cleanest electricity comes from the wind and the sun, (20) ___(3)___. Then there is another big problem; we cannot depend on solar power and the wind, because the sun does not shine at night, and the wind does not blow all the time. These kinds of green power are not reliable, so we need other ideas too.
Climate change (21) ___(4)___. Many countries are now producing less CO2 and less air pollution than they used to. Cars are cleaner, heating is cleaner, more things are being recycled. The problem lies in poorer countries (22) ___(5)___; it also lies in countries like China or Poland or Greece, where coal is still a vital source of energy, of jobs or of exports.