Article: No satisfactory explanation can as yet be given for the exact mechanisms determining the formation of earlywood and latewood. Several factors may be involved. In conifers, at least, rate of growth alone does not determine the proportion of the two portions of the ring, for in some cases the wood of slow growth is very hard and heavy, while in others the opposite is true. The quality of the site where the tree grows undoubtedly affects the character of the wood formed, though it is not possible to formulate a rule governing it. In general, however, it may be said that where strength or ease of working is essential, woods of moderate to slow growth should be chosen.

Question: What counterpart of earlywood are scientists still trying to explain the formation of?
Ans: latewood

Article: The word "animal" comes from the Latin animalis, meaning having breath, having soul or living being. In everyday non-scientific usage the word excludes humans that is, "animal" is often used to refer only to non-human members of the kingdom Animalia; often, only closer relatives of humans such as mammals, or mammals and other vertebrates, are meant. The biological definition of the word refers to all members of the kingdom Animalia, encompassing creatures as diverse as sponges, jellyfish, insects, and humans.

Question: The biological definition of the word animal refers to all member of what kingdom?
Ans: Animalia

Article: Energy gives rise to weight when it is trapped in a system with zero momentum, where it can be weighed. It is also equivalent to mass, and this mass is always associated with it. Mass is also equivalent to a certain amount of energy, and likewise always appears associated with it, as described in mass-energy equivalence. The formula E = mc, derived by Albert Einstein (1905) quantifies the relationship between rest-mass and rest-energy within the concept of special relativity. In different theoretical frameworks, similar formulas were derived by J. J. Thomson (1881), Henri Poincare (1900), Friedrich Hasenohrl (1904) and others (see Mass-energy equivalence#History for further information).

Question: Mass is also equivalent to what?
Ans: certain amount of energy

Article: The northern side of the borough includes the largest park in New York CityPelham Bay Park, which includes Orchard Beachand the fourth largest, Van Cortlandt Park, which is west of Woodlawn Cemetery and borders Yonkers. Also in the northern Bronx, Wave Hill, the former estate of George W. Perkinsknown for a historic house, gardens, changing site-specific art installations and concertsoverlooks the New Jersey Palisades from a promontory on the Hudson in Riverdale. Nearer the borough's center, and along the Bronx River, is Bronx Park; its northern end houses the New York Botanical Gardens, which preserve the last patch of the original hemlock forest that once covered the entire county, and its southern end the Bronx Zoo, the largest urban zoological gardens in the United States. Just south of Van Cortlandt Park is the Jerome Park Reservoir, surrounded by 2 miles (3 km) of stone walls and bordering several small parks in the Bedford Park neighborhood; the reservoir was built in the 1890s on the site of the former Jerome Park Racetrack. Further south is Crotona Park, home to a 3.3-acre (1.3 ha) lake, 28 species of trees, and a large swimming pool. The land for these parks, and many others, was bought by New York City in 1888, while land was still open and inexpensive, in anticipation of future needs and future pressures for development.

Question: How many types of trees are in Crotona Park?
Ans:
28