Tags: animal, portrait, anthonys, poison, arrow, frog, little, guys, dont, grow, bigger, length, skin, produce, alkaloid, substance, medical, researchers, painkiller, times, potent, morphine
Tags: landscape, diablo, lake, located, north, cascades, national, park, rock, falls, nearby, glaciers, water, grinds, powder-like, substance, glacial, flower, turquoise, color
Tags: space, universe, carl, sagans, oft-quoted, billions, galaxiesalso, vast, amount, invisible, substance, called, dark, matterthis, matter, subatomic, particle, dont, interact, electromagnetism, strong, weak, nuclear, forces