Question: Miami has six major causeways that span over Biscayne Bay connecting the western mainland, with the eastern barrier islands along the Atlantic Ocean. The Rickenbacker Causeway is the southernmost causeway and connects Brickell to Virginia Key and Key Biscayne. The Venetian Causeway and MacArthur Causeway connect Downtown with South Beach. The Julia Tuttle Causeway connects Midtown and Miami Beach. The 79th Street Causeway connects the Upper East Side with North Beach. The northernmost causeway, the Broad Causeway, is the smallest of Miami's six causeways, and connects North Miami with Bal Harbour.
Is there an answer to this question: What causeway is closest to the south?

Answer: unanswerable


Question: There are at least two major approaches to understanding cognitive change during adolescence. One is the constructivist view of cognitive development. Based on the work of Piaget, it takes a quantitative, state-theory approach, hypothesizing that adolescents' cognitive improvement is relatively sudden and drastic. The second is the information-processing perspective, which derives from the study of artificial intelligence and attempts to explain cognitive development in terms of the growth of specific components of the thinking process.
Is there an answer to this question: Did Piaget believe that cognitive improvement was sudden and drastic or slow and steadied?

Answer: sudden and drastic


Question: In addition to the use of sound for communication, a wide range of insects have evolved chemical means for communication. These chemicals, termed semiochemicals, are often derived from plant metabolites include those meant to attract, repel and provide other kinds of information. Pheromones, a type of semiochemical, are used for attracting mates of the opposite sex, for aggregating conspecific individuals of both sexes, for deterring other individuals from approaching, to mark a trail, and to trigger aggression in nearby individuals. Allomonea benefit their producer by the effect they have upon the receiver. Kairomones benefit their receiver instead of their producer. Synomones benefit the producer and the receiver. While some chemicals are targeted at individuals of the same species, others are used for communication across species. The use of scents is especially well known to have developed in social insects.:96–105
Is there an answer to this question: Insect chemicals are used to attract and what else?

Answer: repel


Question: A variation of the incandescent lamp did not use a hot wire filament, but instead used an arc struck on a spherical bead electrode to produce heat. The electrode then became incandescent, with the arc contributing little to the light produced. Such lamps were used for projection or illumination for scientific instruments such as microscopes. These arc lamps ran on relatively low voltages and incorporated tungsten filaments to start ionization within the envelope. They provided the intense concentrated light of an arc lamp but were easier to operate. Developed around 1915, these lamps were displaced by mercury and xenon arc lamps.
Is there an answer to this question: What did an alternate version of the incandescent lamp substitute for a wire filament?

Answer:
an arc struck on a spherical bead electrode