Problem: Evidence found in Chinese literature, and archaeological evidence, show that cartography existed in China before the Han. Some of the earliest Han maps discovered were ink-penned silk maps found amongst the Mawangdui Silk Texts in a 2nd-century-BC tomb. The general Ma Yuan created the world's first known raised-relief map from rice in the 1st century AD. This date could be revised if the tomb of Qin Shi Huang is excavated and the account in the Records of the Grand Historian concerning a model map of the empire is proven to be true.
What food stable was the first raised relief map created from?
The answer is the following: rice

Problem: The Byzantine Empire ruled the northern shores of the Sahara from the 5th to the 7th centuries. After the Muslim conquest of Arabia (Arabian peninsula) the Muslim conquest of North Africa began in the mid-7th to early 8th centuries, Islamic influence expanded rapidly on the Sahara. By the end of 641 all of Egypt was in Muslim hands. The trade across the desert intensified. A significant slave trade crossed the desert. It has been estimated that from the 10th to 19th centuries some 6,000 to 7,000 slaves were transported north each year.
What time period did the Muslim conquest of North Africa   take place?
The answer is the following: mid-7th to early 8th centuries

Problem: The U.S. Food and Drug Administration (FDA) has stated that zinc damages nerve receptors in the nose, which can cause anosmia. Reports of anosmia were also observed in the 1930s when zinc preparations were used in a failed attempt to prevent polio infections. On June 16, 2009, the FDA said that consumers should stop using zinc-based intranasal cold products and ordered their removal from store shelves. The FDA said the loss of smell can be life-threatening because people with impaired smell cannot detect leaking gas or smoke and cannot tell if food has spoiled before they eat it. Recent research suggests that the topical antimicrobial zinc pyrithione is a potent heat shock response inducer that may impair genomic integrity with induction of PARP-dependent energy crisis in cultured human keratinocytes and melanocytes.
What can zinc cause damage to in the nose?
The answer is the following: nerve receptors

Problem: To prevent the risk of out-of-phase supplies mixing, sections of line fed from different feeder stations must be kept strictly isolated. This is achieved by Neutral Sections (also known as Phase Breaks), usually provided at feeder stations and midway between them although, typically, only half are in use at any time, the others being provided to allow a feeder station to be shut down and power provided from adjacent feeder stations. Neutral Sections usually consist of an earthed section of wire which is separated from the live wires on either side by insulating material, typically ceramic beads, designed so that the pantograph will smoothly run from one section to the other. The earthed section prevents an arc being drawn from one live section to the other, as the voltage difference may be higher than the normal system voltage if the live sections are on different phases and the protective circuit breakers may not be able to safely interrupt the considerable current that would flow. To prevent the risk of an arc being drawn across from one section of wire to earth, when passing through the neutral section, the train must be coasting and the circuit breakers must be open. In many cases, this is done manually by the drivers. To help them, a warning board is provided just before both the neutral section and an advance warning some distance before. A further board is then provided after the neutral section to tell drivers to re-close the circuit breaker, although drivers must not do this until the rear pantograph has passed this board. In the UK, a system known as Automatic Power Control (APC) automatically opens and closes the circuit breaker, this being achieved by using sets of permanent magnets alongside the track communicating with a detector on the train. The only action needed by the driver is to shut off power and coast and therefore warning boards are still provided at and on the approach to neutral sections.
How were the drivers warned to start coasting the train?
The answer is the following:
warning board