Problem: Please answer a question about the following article about Planck constant:
There are both practical and theoretical difficulties in determining h. The practical difficulties can be illustrated by the fact that the two most accurate methods, the watt balance and the X-ray crystal density method, do not appear to agree with one another. The most likely reason is that the measurement uncertainty for one (or both) of the methods has been estimated too low – it is (or they are) not as precise as is currently believed – but for the time being there is no indication which method is at fault.
Why does this difficulty occur?
A: it is (or they are) not as precise as is currently believed
Problem: Please answer a question about the following article about Slavs:
Jordanes tells us that the Sclaveni had swamps and forests for their cities. Another 6th-century source refers to them living among nearly impenetrable forests, rivers, lakes, and marshes.
Who had swamps and forests for their cities?
A: the Sclaveni
Problem: Please answer a question about the following article about Apollo:
As sun-god and god of light, Apollo was also known by the epithets Aegletes (/əˈɡliːtiːz/ ə-GLEE-teez; Αἰγλήτης, Aiglētēs, from αἴγλη, "light of the sun"), Helius (/ˈhiːliəs/ HEE-lee-əs; Ἥλιος, Helios, literally "sun"), Phanaeus (/fəˈniːəs/ fə-NEE-əs; Φαναῖος, Phanaios, literally "giving or bringing light"), and Lyceus (/laɪˈsiːəs/ ly-SEE-əs; Λύκειος, Lykeios, from Proto-Greek *λύκη, "light"). The meaning of the epithet "Lyceus" later became associated with Apollo's mother Leto, who was the patron goddess of Lycia (Λυκία) and who was identified with the wolf (λύκος), earning him the epithets Lycegenes (/laɪˈsɛdʒəniːz/ ly-SEJ-ə-neez; Λυκηγενής, Lukēgenēs, literally "born of a wolf" or "born of Lycia") and Lycoctonus (/laɪˈkɒktənəs/ ly-KOK-tə-nəs; Λυκοκτόνος, Lykoktonos, from λύκος, "wolf", and κτείνειν, "to kill"). As god of the sun, Apollo was called Sol (/ˈsɒl/ SOL, literally "sun" in Latin) by the Romans.
Since Apollo was known as god of the sun, what was another name for Apollo?
A: Sol
Problem: Please answer a question about the following article about Insect:
Adult insects typically move about by walking, flying, or sometimes swimming (see below, Locomotion). As it allows for rapid yet stable movement, many insects adopt a tripedal gait in which they walk with their legs touching the ground in alternating triangles. Insects are the only invertebrates to have evolved flight. Many insects spend at least part of their lives under water, with larval adaptations that include gills, and some adult insects are aquatic and have adaptations for swimming. Some species, such as water striders, are capable of walking on the surface of water. Insects are mostly solitary, but some, such as certain bees, ants and termites, are social and live in large, well-organized colonies. Some insects, such as earwigs, show maternal care, guarding their eggs and young. Insects can communicate with each other in a variety of ways. Male moths can sense the pheromones of female moths over great distances. Other species communicate with sounds: crickets stridulate, or rub their wings together, to attract a mate and repel other males. Lampyridae in the beetle order Coleoptera communicate with light.
Insects move by walking, flying, and what else?
A:
swimming