BY THE TIME WE ARRIVED AT THE STATION, THE TRAIN HAD LEFT.LONGER....

36. By the time we arrived at the station, the train had left.

longer. We can save more energy by conservation than you can produce for the

TEST 18

same money. Unless we do research on solar energy, wind power, tidal power,

hydroelectric plants, our fossil fuels will run out and we'll all freeze or starve to