QUES: The lateral cut NAB curve was remarkably similar to the NBC Orthacoustic curve that evolved from practices within the National Broadcasting Company since the mid-1930s. Empirically, and not by any formula, it was learned that the bass end of the audio spectrum below 100 Hz could be boosted somewhat to override system hum and turntable rumble noises. Likewise at the treble end beginning at 1,000 Hz, if audio frequencies were boosted by 16 dB at 10,000 Hz the delicate sibilant sounds of speech and high overtones of musical instruments could survive the noise level of cellulose acetate, lacquer/aluminum, and vinyl disc media. When the record was played back using a complementary inverse curve, signal-to-noise ratio was improved and the programming sounded more lifelike.
What bass settings were needed to eliminate hum?

ANS: below 100 Hz

QUES: Some scientific studies suggest that ozone depletion may have a dominant role in governing climatic change in Antarctica (and a wider area of the Southern Hemisphere). Ozone absorbs large amounts of ultraviolet radiation in the stratosphere. Ozone depletion over Antarctica can cause a cooling of around 6 C in the local stratosphere. This cooling has the effect of intensifying the westerly winds which flow around the continent (the polar vortex) and thus prevents outflow of the cold air near the South Pole. As a result, the continental mass of the East Antarctic ice sheet is held at lower temperatures, and the peripheral areas of Antarctica, especially the Antarctic Peninsula, are subject to higher temperatures, which promote accelerated melting. Models also suggest that the ozone depletion/enhanced polar vortex effect also accounts for the recent increase in sea ice just offshore of the continent.
What light does ozone absorb?

ANS: ultraviolet radiation

QUES: Freedom of the press is ostensibly officially guaranteed by the government, but independent press outlets remain restricted, as does a substantial amount of web content. According to the Institute for War & Peace Reporting, access is blocked to local and foreign websites including avesta.tj, Tjknews.com, ferghana.ru, centrasia.ru and journalists are often obstructed from reporting on controversial events. In practice, no public criticism of the regime is tolerated and all direct protest is severely suppressed and does not receive coverage in the local media.
What is not tolerated by the government in respect to media?

ANS: no public criticism of the regime is tolerated

QUES: Although provision is made in Title 10 of the United States Code for the Secretary of the Air Force to appoint warrant officers, the Air Force does not currently use warrant officer grades, and is the only one of the U.S. Armed Services not to do so. The Air Force inherited warrant officer ranks from the Army at its inception in 1947, but their place in the Air Force structure was never made clear.[citation needed] When the Congress authorized the creation of two new senior enlisted ranks in 1958, Air Force officials privately concluded that these two new "super grades" could fill all Air Force needs then performed at the warrant officer level, although this was not publicly acknowledged until years later.[citation needed] The Air Force stopped appointing warrant officers in 1959, the same year the first promotions were made to the new top enlisted grade, Chief Master Sergeant. Most of the existing Air Force warrant officers entered the commissioned officer ranks during the 1960s, but small numbers continued to exist in the warrant officer grades for the next 21 years.
When did the USAF stop appointing warrant officers?

ANS:
1959