Question: Aspirin has been studied extensively in people considered at increased risk of myocardial infarction. Based on numerous studies in different groups (e.g. people with or without diabetes), there does not appear to be a benefit strong enough to outweigh the risk of excessive bleeding. Nevertheless, many clinical practice guidelines continue to recommend aspirin for primary prevention, and some researchers feel that those with very high cardiovascular risk but low risk of bleeding should continue to receive aspirin.
Try to answer this question if possible: Aspirin is recommended for people with a high risk both cardiovascular disease and what?
Answer: unanswerable
Question: A significant and far-reaching shift in human subsistence and lifestyle was to be brought about in areas where crop farming and cultivation were first developed: the previous reliance on an essentially nomadic hunter-gatherer subsistence technique or pastoral transhumance was at first supplemented, and then increasingly replaced by, a reliance upon the foods produced from cultivated lands. These developments are also believed to have greatly encouraged the growth of settlements, since it may be supposed that the increased need to spend more time and labor in tending crop fields required more localized dwellings. This trend would continue into the Bronze Age, eventually giving rise to permanently settled farming towns, and later cities and states whose larger populations could be sustained by the increased productivity from cultivated lands.
Try to answer this question if possible: What trend led to a major shift in the livelihoods of early cultures?
Answer: crop farming and cultivation
Question: On 30 September 1915, troops of the Serbian Army observed three enemy aircraft approaching Kragujevac. Soldiers shot at them with shotguns and machine-guns but failed to prevent them from dropping 45 bombs over the city, hitting military installations, the railway station and many other, mostly civilian, targets in the city. During the bombing raid, private Radoje Ljutovac fired his cannon at the enemy aircraft and successfully shot one down. It crashed in the city and both pilots died from their injuries. The cannon Ljutovac used was not designed as an anti-aircraft gun, it was a slightly modified Turkish cannon captured during the First Balkan War in 1912. This was the first occasion in military history that a military aircraft was shot down with ground-to-air fire.
Try to answer this question if possible: When did Serbian troops notice enemy aircraft approaching Kragujevac? 
Answer: 30 September 1915
Question: David Attenborough was later granted sabbatical leave from his job as Controller to work with the BBC Natural History Unit which had existed since the 1950s. This unit is now famed throughout the world for producing high quality programmes with Attenborough such as Life on Earth, The Private Life of Plants, The Blue Planet, The Life of Mammals, Planet Earth and Frozen Planet.
Try to answer this question if possible: Which group did David Attenborough join while on sabbatical?
Answer:
BBC Natural History Unit