Today's policemen in large cities throughout the world【C1】______on modem inventions to hel

p them in their work. In most places motor scooters and police patrol(巡逻) cars have【C2】______sway with the need to patrol a beat on foot or on horseback. Policemen use telephones,【C3】______located throughout their districts, to make immediate【C4】______with headquarters. Radio, television, and computers【C5】______to speed the work of the modem force. Even boats and helicopters are part of the equipment of metropolitan police departments.

New technical inventions are widely used to【C6】______crime and speed the【C7】______of criminal cases. Electronic computers reduce from hours to minutes the time spent in【C8】______for fingerprints. Witnesses'【C9】______of a criminal are coded and fed【C10】______a computer. The machine then sorts through the picture file of known criminals and selects the name and photograph of the most【C11】______suspect. Lie detectors,【C12】______such evidence is acceptable, are used to【C13】______the truth.

A criminal-identification tool in【C14】______in some places is the image reflector, or "image-maker." This machine【C15】______a picture of a face【C16】______a screen. A detective operates the machine to【C17】______ the parts of the face to match those of the suspect【C18】______described by the witnesses. The final picture is then photographed and sent to police in other areas. Sometimes skilled sketch artists employed by police departments【C19】______oral descriptions into【C20】______of a suspect.

【C1】

A．insist

B．insisting

C．rely

D．relying