Complex sentence: They were sophisticated analog computers whose development reached its zenith during World War II. While rangekeeper technology was used on land, sea, and in the air, the most sophisticated rangekeepers where mounted on warships to direct the fire of long range guns.
Split into simpler sentences: They were sophisticated analog computers whose development reached its zenith during World War II. During World War II, rangekeepers directed gunfire on land, sea, and in the air. While rangekeepers were widely deployed, the most sophisticated rangekeepers where mounted on warships to direct the fire of long range guns.