Use of English · Part 2
Solar energy (0) IS derived ultimately from the sun. It can be divided (1) .......... direct and indirect categories. Most energy sources on Earth are forms of indirect solar energy, (2) .......... we usually don't think of them in that way. Coal, oil and natural gas derived from ancient biological material…
Desbloqueja tots els exàmens, simulacions il·limitades, les 80 fases del joc i molt més.