Practice Test 31: How Glass Changed Architecture and Learning a Language as an Adult

A Glass has been made for thousands of years, but for most of that time large, clear panes were difficult and expensive to produce. Early window glass was small, uneven and often slightly green, which is why old buildings have many small panes held in frames.

B The change came in the middle of the twentieth century. In the float process, developed by the British engineer Alastair Pilkington, molten glass is poured onto a bath of molten tin. The glass spreads out and floats, and because the surface of the tin is perfectly flat, the glass cools into smooth sheets of even thickness. The process is still the main way in which window glass is made.

C Cheap, flat glass allowed architects to hang a thin skin of glass on the front of a tall building, an approach known as a curtain wall. Glass towers let in daylight and give views, but they also have drawbacks. They can gain heat from the sun and need a lot of energy for cooling. Designers now use coatings, double glazing and shading to reduce the problem.

D Another problem is less obvious. Birds cannot always see clear glass and may fly into it, especially when trees are reflected in the surface. Some cities now ask for patterned glass on new buildings, and designers add fine lines or dots that people hardly notice but that birds can see.

A Many people believe that children learn languages more easily than adults, and in some respects they do. Children who move to a new country often end up with a native-like accent, and they seem to learn without effort. Adults rarely sound exactly like native speakers, however long they live abroad.

B The picture is more mixed than it looks. In the first months of learning, adults and older teenagers often progress faster than young children, because they can use study skills, understand grammar rules and apply memory techniques. Children, on the other hand, usually catch up and overtake them over several years, mainly because they spend far more hours listening to the language.

C What matters most for adults is not age but time, motivation and the quality of practice. Adults often have limited time and may be embarrassed to make mistakes, which reduces the practice that language learning needs. Those who live in the country, use the language every day for work and are willing to speak with others make the fastest progress.

D Teachers therefore advise adults to study little and often, to listen to a lot of real speech and to speak from the beginning, even when it feels difficult. Twenty minutes every day is more useful than a long weekly lesson, and joining a group or finding a conversation partner provides the practice that books cannot.