忍不住: cannot help, unable to bear...
投机: to speculate (on financial markets), opportunistic, congenial, agreeable...
传染: to infect, contagious...
未: not yet, did not, have not, not...
印刷术: printing, printing technology...
昏: faint; lose consciousness; dusk; twilight; dull; muddle-headed...
足迹: footprint, track, spoor...
涂抹: to paint, to smear, to apply (makeup etc), to doodle, to erase, to obliterate...
