Problem: It is thought that annelids were originally animals with two separate sexes, which released ova and sperm into the water via their nephridia. The fertilized eggs develop into trochophore larvae, which live as plankton. Later they sink to the sea-floor and metamorphose into miniature adults: the part of the trochophore between the apical tuft and the prototroch becomes the prostomium (head); a small area round the trochophore's anus becomes the pygidium (tail-piece); a narrow band immediately in front of that becomes the growth zone that produces new segments; and the rest of the trochophore becomes the peristomium (the segment that contains the mouth).
What do annelid eggs become?
The answer is the following: trochophore larvae

Problem: Since incandescent light bulbs use more energy than alternatives such as CFLs and LED lamps, many governments have introduced measures to ban their use, by setting minimum efficacy standards higher than can be achieved by incandescent lamps. Measures to ban light bulbs have been implemented in the European Union, the United States, Russia, Brazil, Argentina, Canada and Australia, among others. In the Europe the EC has calculated that the ban contributes 5 to 10 billion euros to the economy and saves 40 TWh of electricity every year, translating in CO2 emission reductions of 15 million tonnes.
How much does the incandescent light ban in Europe contribute to the economy each year?
The answer is the following: 5 to 10 billion euros

Problem: The major landmark of puberty for males is the first ejaculation, which occurs, on average, at age 13. For females, it is menarche, the onset of menstruation, which occurs, on average, between ages 12 and 13. The age of menarche is influenced by heredity, but a girl's diet and lifestyle contribute as well. Regardless of genes, a girl must have a certain proportion of body fat to attain menarche. Consequently, girls who have a high-fat diet and who are not physically active begin menstruating earlier, on average, than girls whose diet contains less fat and whose activities involve fat reducing exercise (e.g. ballet and gymnastics). Girls who experience malnutrition or are in societies in which children are expected to perform physical labor also begin menstruating at later ages.
Besides heredity, what other factors contribute to when menustration begins?
The answer is the following: diet and lifestyle

Problem: Situated on one of the world's largest natural harbors, New York City consists of five boroughs, each of which is a separate county of New York State. The five boroughs – Brooklyn, Queens, Manhattan, the Bronx, and Staten Island – were consolidated into a single city in 1898. With a census-estimated 2014 population of 8,491,079 distributed over a land area of just 305 square miles (790 km2), New York is the most densely populated major city in the United States. As many as 800 languages are spoken in New York, making it the most linguistically diverse city in the world. By 2014 census estimates, the New York City metropolitan region remains by a significant margin the most populous in the United States, as defined by both the Metropolitan Statistical Area (20.1 million residents) and the Combined Statistical Area (23.6 million residents). In 2013, the MSA produced a gross metropolitan product (GMP) of nearly US$1.39 trillion, while in 2012, the CSA generated a GMP of over US$1.55 trillion, both ranking first nationally by a wide margin and behind the GDP of only twelve and eleven countries, respectively.
In 2014, what did the census estimate the population of New York City to be?
The answer is the following:
8,491,079