Problem: There are a number of proposals to redefine certain of the SI base units in terms of fundamental physical constants. This has already been done for the metre, which is defined in terms of a fixed value of the speed of light. The most urgent unit on the list for redefinition is the kilogram, whose value has been fixed for all science (since 1889) by the mass of a small cylinder of platinum–iridium alloy kept in a vault just outside Paris. While nobody knows if the mass of the International Prototype Kilogram has changed since 1889 – the value 1 kg of its mass expressed in kilograms is by definition unchanged and therein lies one of the problems – it is known that over such a timescale the many similar Pt–Ir alloy cylinders kept in national laboratories around the world, have changed their relative mass by several tens of parts per million, however carefully they are stored, and the more so the more they have been taken out and used as mass standards. A change of several tens of micrograms in one kilogram is equivalent to the current uncertainty in the value of the Planck constant in SI units.
What measurement is deemed most important to redefine in terms of physical constants?
The answer is the following: the kilogram

Problem: Unauthorized MP3 file sharing continues on next-generation peer-to-peer networks. Some authorized services, such as Beatport, Bleep, Juno Records, eMusic, Zune Marketplace, Walmart.com, Rhapsody, the recording industry approved re-incarnation of Napster, and Amazon.com sell unrestricted music in the MP3 format.
Which format is used by the companies that sell the music legally?
The answer is the following: MP3

Problem: Traditionally a sea-power, Portugal has had a strong tradition in the Portuguese fishing sector and is one of the countries with the highest fish consumption per capita. The main landing sites in Portugal (including Azores and Madeira), according to total landings in weight by year, are the harbours of Matosinhos, Peniche, Olhão, Sesimbra, Figueira da Foz, Sines, Portimão and Madeira. Portuguese processed fish products are exported through several companies, under a number of different brands and registered trademarks, such as Ramirez (the world’s oldest active canned fish producer), Bom Petisco, Nero, Combate, Comur, General, Líder, Manná, Murtosa, Pescador, Pitéu, Tenório, Torreira and Vasco da Gama.[citation needed]
What are the names of various companies that produce and export fish products?
The answer is the following: Bom Petisco, Nero, Combate, Comur, General, Líder, Manná, Murtosa, Pescador, Pitéu, Tenório, Torreira and Vasco da Gama

Problem: A resin used for making non-wrinkle shirts releases formaldehyde, which could cause contact dermatitis for some people; no disclosure requirements exist, and in 2008 the U.S. Government Accountability Office tested formaldehyde in clothing and found that generally the highest levels were in non-wrinkle shirts and pants. In 1999, a study of the effect of washing on the formaldehyde levels found that after 6 months after washing, 7 of 27 shirts had levels in excess of 75 ppm, which is a safe limit for direct skin exposure.
How many months of washing did a 1999 study look at?
The answer is the following:
6