"I needed to keep a roof over my children's heads".
Demographers say a rate of 2.1 is needed to keep a population from declining.
Mr. Brewster said publishers needed to keep a diverse stable of magazines.
This implies that to ensure in a workable field-emission device fabricated by graphene nanoribbon, a wider nanoribbon is needed to keep a large field-emission current density.
A continuous application of force is needed to keep a fluid flowing, just as a continuous force is needed to keep a solid body moving in the presence of friction.
The administration argues this will be needed to keep a balanced portfolio of debts of different maturities.
Britain needed to keep a deterrent to maintain a voice in international nuclear weapons negotiations, he told the Guardian.
He angrily suspended negotiations over the bilateral security agreement that is needed to keep a residual American force in Afghanistan after the combat troops have left.
Deep Space 1's ion motor, by contrast, produces only the amount of force needed to keep a piece of paper in the air by blowing on it.
Indeed, more than half of the energy needed to keep a truck moving at highway speeds is expended just to overcome aerodynamic drag, the laboratory's report says.
Today, almost no place in the developed world has a total fertility rate of 2.1 children, the replacement rate needed to keep a population from declining.
