V.use the appropriate expressions above to complete these sentences.
show that by 2050 the world’s population will be 3.5 billion.
2 scientists as the harmonious coexistence between organisms and their environment.
are caused by global warming and the greenhouse effect.
is a renewable energy source that converts the energy of tides into electricity.
5 taking two bottles to for recycling saves enough energy to boil water for five cups of tea.
6 since people need more and more land for are being cleared at an alarming rate.