This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.
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Question: Passage: The school has many nationally and internationally acclaimed scholars in social security, health care, health disparities, communication, social and health policy, and individual and family development. Many of the faculty have training in both social work and public health. The school's current dean is Edward F. Lawlor. In addition to affiliation with the university-wide Institute of Public Health, Brown houses 12 research centers. The Brown School Library collects materials on many topics, with specific emphasis on: children, youth, and families; gerontology; health; mental health; social and economic development; family therapy; and management. The library maintains subscriptions to over 450 academic journals.

Answer: How many academic journal subscriptions does the Brown School Library have for mental health issues?


Question: Passage: Many pesticides can be grouped into chemical families. Prominent insecticide families include organochlorines, organophosphates, and carbamates. Organochlorine hydrocarbons (e.g., DDT) could be separated into dichlorodiphenylethanes, cyclodiene compounds, and other related compounds. They operate by disrupting the sodium/potassium balance of the nerve fiber, forcing the nerve to transmit continuously. Their toxicities vary greatly, but they have been phased out because of their persistence and potential to bioaccumulate.:239–240 Organophosphate and carbamates largely replaced organochlorines. Both operate through inhibiting the enzyme acetylcholinesterase, allowing acetylcholine to transfer nerve impulses indefinitely and causing a variety of symptoms such as weakness or paralysis. Organophosphates are quite toxic to vertebrates, and have in some cases been replaced by less toxic carbamates.:136–137 Thiocarbamate and dithiocarbamates are subclasses of carbamates. Prominent families of herbicides include phenoxy and benzoic acid herbicides (e.g. 2,4-D), triazines (e.g., atrazine), ureas (e.g., diuron), and Chloroacetanilides (e.g., alachlor). Phenoxy compounds tend to selectively kill broad-leaf weeds rather than grasses. The phenoxy and benzoic acid herbicides function similar to plant growth hormones, and grow cells without normal cell division, crushing the plant's nutrient transport system.:300 Triazines interfere with photosynthesis.:335 Many commonly used pesticides are not included in these families, including glyphosate.

Answer: What did glyphosate take the place of?


Question: Passage: Baran developed the concept of distributed adaptive message block switching during his research at the RAND Corporation for the US Air Force into survivable communications networks, first presented to the Air Force in the summer of 1961 as briefing B-265, later published as RAND report P-2626 in 1962, and finally in report RM 3420 in 1964. Report P-2626 described a general architecture for a large-scale, distributed, survivable communications network. The work focuses on three key ideas: use of a decentralized network with multiple paths between any two points, dividing user messages into message blocks, later called packets, and delivery of these messages by store and forward switching.

Answer:
What was developed in the summer of 1961?