This theory required that the blood be consumed and produced many times over.

The just-war theory requires that a threat be imminent before an attack is started.

The theory in this book often requires choice principles.

Others say that the theory may require complex movement rules that are too difficult for an animal to follow.

Some theories require it to be at least eleven dimensions.

The theory required at least one of the three major market indicators to finish 1987 higher than 1986.

This theory requires an account to be given of this central distinction.

The one fact is evident, both theories require a leap of faith to believe.

Yet it was so easy to depend on someone else when not all theories required an expert.