Context: In the 20th century, new types of glass such as laminated glass, reinforced glass and glass bricks have increased the use of glass as a building material and resulted in new applications of glass. Multi-storey buildings are frequently constructed with curtain walls made almost entirely of glass. Similarly, laminated glass has been widely applied to vehicles for windscreens. While glass containers have always been used for storage and are valued for their hygienic properties, glass has been utilized increasingly in industry. Optical glass for spectacles has been used since the late Middle Ages. The production of lenses has become increasingly proficient, aiding astronomers as well as having other application in medicine and science. Glass is also employed as the aperture cover in many solar energy systems.

Question: What type of glass is used in cars?
Answer: laminated

Question: When did eyeglasses originate?
Answer: late Middle Ages

Question: The walls of skyscrapers are often made of what material?
Answer: glass

Question: What type of power systems use glass?
Answer: solar

Question: What type of scientists rely on glass for distant observations?
Answer: astronomers

Question: What type of glass is used in aperture covers?
Answer: Unanswerable

Question: When did multi-storey buildings originate?
Answer: Unanswerable

Question: Walls used for storage are often made of what material?
Answer: Unanswerable

Question: What type of power systems use curtains?
Answer: Unanswerable

Question: What type of scientists rely on windscreens for distant observations?
Answer: Unanswerable