Certain special attacks require minimum numbers of weapons, or specific types.

"An attack on a whole class of people requires that special action be taken."

Knowing this is important, because severe attacks may require emergency treatment.

Each attack, however small, almost always requires the convoy to stop, if only to allow its soldiers to respond.

Furthermore, such attacks require only a single access to the system that is being compromised.

Remember that this attack requires a high degree of coordination.

This attack, beyond question, required that the Sheriff investigate personally.

Severe attacks are less common but last longer and require immediate medical help.

A severe attack may require that the person be hospitalized for treatment.

The attack, in June 2006, required him to receive hospital treatment.