The British adopted "effective ceiling", meaning the altitude at which a gun could deliver a series of shells against a moving target; this could be constrained by maximum fuse running time as well as the gun's capability. By the late 1930s the British definition was "that height at which a directly approaching target at 400 mph (=643.6 km/h) can be engaged for 20 seconds before the gun reaches 70 degrees elevation". However, effective ceiling for heavy AA guns was affected by non-ballistic factors:
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Who adopted the use of the term, effective ceiling?
Ah, so.. The British

The most expensive part of a CD is the jewel case. In 1995, material costs were 30 cents for the jewel case and 10 to 15 cents for the CD. Wholesale cost of CDs was $0.75 to $1.15, which retailed for $16.98. On average, the store received 35 percent of the retail price, the record company 27 percent, the artist 16 percent, the manufacturer 13 percent, and the distributor 9 percent. When 8-track tapes, cassette tapes, and CDs were introduced, each was marketed at a higher price than the format they succeeded, even though the cost to produce the media was reduced. This was done because the apparent value increased. This continued from vinyl to CDs but was broken when Apple marketed MP3s for $0.99, and albums for $9.99. The incremental cost, though, to produce an MP3 is very small.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): When did Apple place MP3s on the market?
Ah, so.. unanswerable

Palawan Island, between Borneo and Mindoro, the fifth largest and western-most Philippine Island, was invaded on 28 February with landings of the Eighth Army at Puerto Princesa. The Japanese put up little direct defense of Palawan, but cleaning up pockets of Japanese resistance lasted until late April, as the Japanese used their common tactic of withdrawing into the mountain jungles, dispersed as small units. Throughout the Philippines, U.S. forces were aided by Filipino guerrillas to find and dispatch the holdouts.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What is the western-most Philippine island?
Ah, so..
Palawan