Question: Read this and answer the question

Albert Einstein lived in a flat at the Kramgasse 49, the site of the Einsteinhaus, from 1903 to 1905, the year in which the Annus Mirabilis Papers were published.

What is the flat that Einstein called?
Answer: Einsteinhaus
Question: Read this and answer the question

Despite some concerns, western vegetarians and vegans have not been found to suffer from overt zinc deficiencies any more than meat-eaters. Major plant sources of zinc include cooked dried beans, sea vegetables, fortified cereals, soyfoods, nuts, peas, and seeds. However, phytates in many whole-grains and fiber in many foods may interfere with zinc absorption and marginal zinc intake has poorly understood effects. The zinc chelator phytate, found in seeds and cereal bran, can contribute to zinc malabsorption. There is some evidence to suggest that more than the US RDA (15 mg) of zinc daily may be needed in those whose diet is high in phytates, such as some vegetarians. These considerations must be balanced against the fact that there is a paucity of adequate zinc biomarkers, and the most widely used indicator, plasma zinc, has poor sensitivity and specificity. Diagnosing zinc deficiency is a persistent challenge.

What is found in whole grains that can interfere with zinc absorption?
Answer: phytates
Question: Read this and answer the question

A solar balloon is a black balloon that is filled with ordinary air. As sunlight shines on the balloon, the air inside is heated and expands causing an upward buoyancy force, much like an artificially heated hot air balloon. Some solar balloons are large enough for human flight, but usage is generally limited to the toy market as the surface-area to payload-weight ratio is relatively high.

Why is the use of solar balloons typically limited to the toy market?
Answer:
the surface-area to payload-weight ratio is relatively high