var vocab = new Array(815);

vocab[0]="a horizon";
vocab[1]="aa";
vocab[2]="ablation area";
vocab[3]="abrasion";
vocab[4]="absolute age";

vocab[5]="absolute magnitude";
vocab[6]="absorption nebula";

var def = new Array(815);
 
def[0]="The uppermost layer of soil composed of a mixture of organic matter and leached and weathered minerals.";

def[1]="A lava flow that has a jagged, rubbly, broken surface.";
def[2]="The lower portion of a glacier where more snow melts in summer than accumulates in winter so there is a net loss of glacial ice.";

def[3]="The mechanical wearing and grinding of rock surfaces by friction and impact.";
def[4]="Time measured in years.";
def[5]="The brightness that a star would appear to have if it were 32 light-years (10 parsecs) away.";

def[6]="A cold nebula that absorbs light.";

var sr = Math.floor(Math.random() * 815);
var voc = vocab[sr];
var define = def[sr];