The authors habitually think of immigrants filling educationally graded slots in some pre-determined economy.

ECONOMIST: Immigration

You can enhance this even further by filling up those lower tax brackets from pre-tax accounts and dipping into Roth accounts for the higher brackets.

FORBES: What's Really Jeopardizing Your Retirement?

The tooth is from a jawbone that was found in a cave near the village of Lonche, Slovenia and is considered one of the most ancient evidence of pre-historic dentistry and the earliest known direct example of therapeutic-palliative dental filling so far.

UNESCO: Basic Sciences

If Apple started filling the education channel with iPad2s, it would simply, totally and forever more pre-empt competition.

FORBES: How Apple Can Do Good & Screw Its Competition