Problem: Matter:

There is an entire literature concerning the "structure of matter", ranging from the "electrical structure" in the early 20th century, to the more recent "quark structure of matter", introduced today with the remark: Understanding the quark structure of matter has been one of the most important advances in contemporary physics.[further explanation needed] In this connection, physicists speak of matter fields, and speak of particles as "quantum excitations of a mode of the matter field". And here is a quote from de Sabbata and Gasperini: "With the word "matter" we denote, in this context, the sources of the interactions, that is spinor fields (like quarks and leptons), which are believed to be the fundamental components of matter, or scalar fields, like the Higgs particles, which are used to introduced mass in a gauge theory (and that, however, could be composed of more fundamental fermion fields)."[further explanation needed]

When did de Sabbata and Gasperini write?
---
A: unanswerable

Problem: Flowering plant:

Fossilized spores suggest that higher plants (embryophytes) have lived on land for at least 475 million years. Early land plants reproduced sexually with flagellated, swimming sperm, like the green algae from which they evolved. An adaptation to terrestrialization was the development of upright meiosporangia for dispersal by spores to new habitats. This feature is lacking in the descendants of their nearest algal relatives, the Charophycean green algae. A later terrestrial adaptation took place with retention of the delicate, avascular sexual stage, the gametophyte, within the tissues of the vascular sporophyte. This occurred by spore germination within sporangia rather than spore release, as in non-seed plants. A current example of how this might have happened can be seen in the precocious spore germination in Selaginella, the spike-moss. The result for the ancestors of angiosperms was enclosing them in a case, the seed. The first seed bearing plants, like the ginkgo, and conifers (such as pines and firs), did not produce flowers. The pollen grains (males) of Ginkgo and cycads produce a pair of flagellated, mobile sperm cells that "swim" down the developing pollen tube to the female and her eggs.

What did Charophycean green algae develop to disperse by spores into new habitats?
---
A: unanswerable

Problem: Northwestern University:

In the fall of 2014, among the six undergraduate schools, 40.6% of undergraduate students are enrolled in the Weinberg College of Arts and Sciences, 21.3% in the McCormick School of Engineering and Applied Science, 14.3% in the School of Communication, 11.7% in the Medill School of Journalism, 5.7% in the Bienen School of Music, and 6.4% in the School of Education and Social Policy. The five most commonly awarded undergraduate degrees are in economics, journalism, communication studies, psychology, and political science. While professional students are affiliated with their respective schools, the School of Professional Studies offers master's and bachelor's degree, and certificate programs tailored to the professional studies. With 2,446 students enrolled in science, engineering, and health fields, the largest graduate programs by enrollment include chemistry, integrated biology, material sciences, electrical and computer engineering, neuroscience, and economics. The Kellogg School of Management's MBA, the School of Law's JD, and the Feinberg School of Medicine's MD are the three largest professional degree programs by enrollment.

In the fall of 2011, which school did 21.3% of undergraduates enroll in?
---
A: unanswerable

Problem: Jehovah%27s Witnesses:

Meetings for worship and study are held at Kingdom Halls, which are typically functional in character, and do not contain religious symbols. Witnesses are assigned to a congregation in whose "territory" they usually reside and attend weekly services they refer to as "meetings" as scheduled by congregation elders. The meetings are largely devoted to study of Watch Tower Society literature and the Bible. The format of the meetings is established by the religion's headquarters, and the subject matter for most meetings is the same worldwide. Congregations meet for two sessions each week comprising five distinct meetings that total about three-and-a-half hours, typically gathering mid-week (three meetings) and on the weekend (two meetings). Prior to 2009, congregations met three times each week; these meetings were condensed, with the intention that members dedicate an evening for "family worship". Gatherings are opened and closed with kingdom songs (hymns) and brief prayers. Twice each year, Witnesses from a number of congregations that form a "circuit" gather for a one-day assembly. Larger groups of congregations meet once a year for a three-day "regional convention", usually at rented stadiums or auditoriums. Their most important and solemn event is the commemoration of the "Lord's Evening Meal", or "Memorial of Christ's Death" on the date of the Jewish Passover.

What are Jehovah Witnesses' gatherings opened and closed with?
---
A:
songs (hymns) and brief prayers