The British dealt with range measurement first, when it was realised that range was the key to producing a better fuse setting. This led to the Height/Range Finder (HRF), the first model being the Barr & Stroud UB2, a 2-metre optical coincident rangefinder mounted on a tripod. It measured the distance to the target and the elevation angle, which together gave the height of the aircraft. These were complex instruments and various other methods were also used. The HRF was soon joined by the Height/Fuse Indicator (HFI), this was marked with elevation angles and height lines overlaid with fuse length curves, using the height reported by the HRF operator, the necessary fuse length could be read off.
What was the first model of HRF (Height Range Finder) used by the British?
Barr & Stroud UB2

The eligible age-range for contestants is currently fifteen to twenty-eight years old. The initial age limit was sixteen to twenty-four in the first three seasons, but the upper limit was raised to twenty-eight in season four, and the lower limit was reduced to fifteen in season ten. The contestants must be legal U.S. residents, cannot have advanced to particular stages of the competition in previous seasons (varies depending on the season, currently by the semi-final stage until season thirteen), and must not hold any current recording or talent representation contract by the semi-final stage (in previous years by the audition stage).
What is the upper age limit for contestants on American Idol?
twenty-eight

DST has mixed effects on health. In societies with fixed work schedules it provides more afternoon sunlight for outdoor exercise. It alters sunlight exposure; whether this is beneficial depends on one's location and daily schedule, as sunlight triggers vitamin D synthesis in the skin, but overexposure can lead to skin cancer. DST may help in depression by causing individuals to rise earlier, but some argue the reverse. The Retinitis Pigmentosa Foundation Fighting Blindness, chaired by blind sports magnate Gordon Gund, successfully lobbied in 1985 and 2005 for US DST extensions.
What do societies with standardized work schedules have more time for because of the increase in afternoon daylight from DST?
outdoor exercise