Select all the correct answers. which two geographic features prevented enemies from attacking china? the gobi desert the himalayas the yangtze river the huang he river the tibetan plateau

Which of these was an accomplishment of the han dynasty? the invention of the seismograph finding a water passage to europe the invention of the ballpoint pen the invention of the abacus

What affected the second industrial revolution have on transportation

Which suggests the most critical aspect of the peak oil theory? 1) controversy rages over rumors that the fracking lobby in washington has influenced the statistics. 2) supporters and critics argue endlessly over the rate of extraction and shape of the bell curve. 3) saudi arabia will soon have to begin fracking, leading to protests and further destabilization. 4) a new oil discovery means a fresh peak cycle, making that region the target of aggressors.