When the number of passengers requires it, additional trains may be added also.

At the current time the department's call volume and number of volunteers does not require a need for a 5th station.

It is not as easy to say yes because, let's be honest, a number of other programs don't require a financial investment up front.

The increased number of awards would require a longer programme - good.

A large number of crystals increases cost and requires greater space.

The large number of visitors to this library soon required that it be expanded.

The number of drivers required to compete in each race.

The number of changes had required all of them to adapt.

A small number of other issues require further scientific analysis before they can be implemented practically.

A number of them require helmets for children 12 and under, while others strongly encourage their use.