Problem: United States dollar:

The U.S. dollar is fiat money. It is the currency most used in international transactions and is the world's most dominant reserve currency. Several countries use it as their official currency, and in many others it is the de facto currency. Besides the United States, it is also used as the sole currency in two British Overseas Territories in the Caribbean: the British Virgin Islands and the Turks and Caicos islands. A few countries use only the U.S. Dollar for paper money, while the country mints its own coins, or also accepts U.S. coins that can be used as payment in U.S. dollars, such as the Susan B. Anthony dollar.

What kind of money is the Caribbean dollar?
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A: unanswerable

Problem: Railway electrification system:

Disadvantages of electric traction include high capital costs that may be uneconomic on lightly trafficked routes; a relative lack of flexibility since electric trains need electrified tracks or onboard supercapacitors and charging infrastructure at stations; and a vulnerability to power interruptions. Different regions may use different supply voltages and frequencies, complicating through service. The limited clearances available under catenaries may preclude efficient double-stack container service. The lethal voltages on contact wires and third rails are a safety hazard to track workers, passengers and trespassers. Overhead wires are safer than third rails, but they are often considered unsightly.

What is a safety hazard to track workers?
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A: voltages on contact wires

Problem: Guam:

Despite Magellan's visit, Guam was not officially claimed by Spain until January 26, 1565 by General Miguel Lopez de Legazpi.:46 From 1565 to 1815, Guam and the Northern Mariana Islands, the only Spanish outpost in the Pacific Ocean east of the Philippines, was an important resting stop for the Manila galleons, a fleet that covered the Pacific trade route between Acapulco and Manila.:51 To protect these Pacific fleets, Spain built several defensive structures which are still standing today, such as Fort Nuestra Senora de la Soledad in Umatac. It is the biggest single segment of Micronesia, the largest islands between the island of Kyushu (Japan), New Guinea, the Philippines, and the Hawaiian Islands.

In what country is Acapulco?
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A: unanswerable

Problem: Infection:

One of the ways to prevent or slow down the transmission of infectious diseases is to recognize the different characteristics of various diseases. Some critical disease characteristics that should be evaluated include virulence, distance traveled by victims, and level of contagiousness. The human strains of Ebola virus, for example, incapacitate their victims extremely quickly and kill them soon after. As a result, the victims of this disease do not have the opportunity to travel very far from the initial infection zone. Also, this virus must spread through skin lesions or permeable membranes such as the eye. Thus, the initial stage of Ebola is not very contagious since its victims experience only internal hemorrhaging. As a result of the above features, the spread of Ebola is very rapid and usually stays within a relatively confined geographical area. In contrast, the Human Immunodeficiency Virus (HIV) kills its victims very slowly by attacking their immune system. As a result, many of its victims transmit the virus to other individuals before even realizing that they are carrying the disease. Also, the relatively low virulence allows its victims to travel long distances, increasing the likelihood of an epidemic.

What are some critical disease characteristics that should be evaluated?
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A:
virulence, distance traveled by victims, and level of contagiousness