Question: Persistent infections occur because the body is unable to clear the organism after the initial infection. Persistent infections are characterized by the continual presence of the infectious organism, often as latent infection with occasional recurrent relapses of active infection. There are some viruses that can maintain a persistent infection by infecting different cells of the body. Some viruses once acquired never leave the body. A typical example is the herpes virus, which tends to hide in nerves and become reactivated when specific circumstances arise.
Is there an answer to this question: Why do persistent infections occur?

Answer: body is unable to clear the organism after the initial infection

Question: Law enforcement, however, constitutes only part of policing activity. Policing has included an array of activities in different situations, but the predominant ones are concerned with the preservation of order. In some societies, in the late 18th and early 19th centuries, these developed within the context of maintaining the class system and the protection of private property. Many police forces suffer from police corruption to a greater or lesser degree. The police force is usually a public sector service, meaning they are paid through taxes.
Is there an answer to this question: When were police used to protect the class system?

Answer: late 18th and early 19th centuries

Question: Saint Athanasius of Alexandria (/nes/; Greek: , Athanasios Alexandrias; c. 296298 2 May 373), also called Athanasius the Great, Athanasius the Confessor or, primarily in the Coptic Orthodox Church, Athanasius the Apostolic, was the twentieth bishop of Alexandria (as Athanasius I). His episcopate lasted 45 years (c. 8 June 328 2 May 373), of which over 17 were spent in five exiles ordered by four different Roman emperors. Athanasius is a renowned Christian theologian, a Church Father, the chief defender of Trinitarianism against Arianism, and a noted Egyptian leader of the fourth century.
Is there an answer to this question: When did Saint Athanasius die?

Answer: 2 May 373

Question: Families and households were still largely independent economically, and the household was probably the center of life. However, excavations in Central Europe have revealed that early Neolithic Linear Ceramic cultures ("Linearbandkeramik") were building large arrangements of circular ditches between 4800 BC and 4600 BC. These structures (and their later counterparts such as causewayed enclosures, burial mounds, and henge) required considerable time and labour to construct, which suggests that some influential individuals were able to organise and direct human labour though non-hierarchical and voluntary work remain possibilities.
Is there an answer to this question: What features about the ditches suggests that it was built by people under a leader's command?

Answer:
required considerable time and labour to construct