Problem: Question: "Which major isotope of uranium is the most common?" Context: "Natural uranium consists of three major isotopes: uranium-238 (99.28% natural abundance), uranium-235 (0.71%), and uranium-234 (0.0054%). All three are radioactive, emitting alpha particles, with the exception that all three of these isotopes have small probabilities of undergoing spontaneous fission, rather than alpha emission. There are also five other trace isotopes: uranium-239, which is formed when 238U undergoes spontaneous fission, releasing neutrons that are captured by another 238U atom; uranium-237, which is formed when 238U captures a neutron but emits two more, which then decays to neptunium-237; uranium-233, which is formed in the decay chain of that neptunium-237; and finally, uranium-236 and -240, which appear in the decay chain of primordial plutonium-244. It is also expected that thorium-232 should be able to undergo double beta decay, which would produce uranium-232, but this has not yet been observed experimentally." Answer:

A: uranium-238

Problem: Question: "Poultry kept for companionship are?" Context: "Poultry (/poltri/) are domesticated birds kept by humans for the eggs they produce, their meat, their feathers, or sometimes as pets. These birds are most typically members of the superorder Galloanserae (fowl), especially the order Galliformes (which includes chickens, quails and turkeys) and the family Anatidae, in order Anseriformes, commonly known as "waterfowl" and including domestic ducks and domestic geese. Poultry also includes other birds that are killed for their meat, such as the young of pigeons (known as squabs) but does not include similar wild birds hunted for sport or food and known as game. The word "poultry" comes from the French/Norman word poule, itself derived from the Latin word pullus, which means small animal." Answer:

A: pets

Problem: Question: "What has happened to the model suggesting that one gene makes one protein?" Context: "Early work in molecular genetics suggested the model that one gene makes one protein. This model has been refined since the discovery of genes that can encode multiple proteins by alternative splicing and coding sequences split in short section across the genome whose mRNAs are concatenated by trans-splicing." Answer:

A: refined

Problem: Question: "Where do certain goods that are taken to remote areas come from?" Context: "Many communities have small air taxi services. These operations originated from the demand for customized transport to remote areas. Perhaps the most quintessentially Alaskan plane is the bush seaplane. The world's busiest seaplane base is Lake Hood, located next to Ted Stevens Anchorage International Airport, where flights bound for remote villages without an airstrip carry passengers, cargo, and many items from stores and warehouse clubs. In 2006 Alaska had the highest number of pilots per capita of any U.S. state." Answer:

A:
stores and warehouse clubs