Scientists have designed “transparent wood” that could replace conventional glass in windows.

D
Scientists have designed “transparent wood” that could replace conventional glass in windows. The innovation was developed using wood from the balsa tree, which is native to South and Central America, and claims to be five times more thermally efficient than glass.
The team treated balsa wood in an oxidizing bath that bleaches it of nearly all visibility and then penetrated（渗透） it with a synthetic polymer (合成聚合物) called polyvinyl alcohol (PVA), creating a product that is virtually transparent. Unlike traditional glass, the transparent wood can bear much stronger impacts and will bend or break when damaged, instead of shattering.
The transparent wood was created by teams at the University of Maryland and University of Colorado, which set out to find a greener alternative to conventional glass – a production that creates 25,000 tons in emissions each year.
Along with contributing to greenhouse gases, glass contributes to a loss of energy. Residential building windows in particular account for 10-25% of the heat loss due to their poor thermal management capability, the team wrote in the study. Exploring energy efficient window materials is thus highly desirable to address heating costs, energy shortages, and the global impact of climate change associated with increased carbon emissions.
The team notes that the bonding between PVA and cellulose in the wood, creates a tightly packed structure that allows for more thermal protection and makes it more long-lived and lighter than glass.
“Switching to transparent wood could prove to be cost efficient as well,” researchers shared in a statement. It is approximately five times more thermally efficient than glass, cutting energy costs. It is made from a sustainable, renewable resource with low carbon emissions. It’s also compatible with existing industrial processing equipment, making the transition into manufacturing an easy prospect.
32. What is the meaning of “transparent” in paragraph 1?
A. man-made B. as clear as glass
C. energy–saving D. environmentally-friendly
33. Which of the following about “transparent wood” is NOT true?
A. The material of it comes from a balsa tree in nature.
B. It won’t break into pieces even when damaged.
C. It is easier to lose heat to cool the room in summer.
D. It is lighter and can be used longer than glass.
34. What’s the text mainly about?
A. A new way to produce transparent wood .
B. Transparent wood’s advantage over conventional glass.
C. A kind of tough wood is discovered.
D. More balsa trees will be planted.
35. What is the purpose of inventing “transparent wood”?
A. to save cost and make more money.
B. to replace air conditioner and save energy.
C. to cut down greenhouse gas to protect environment.
D. to find a greener choice to replace glass.
参考答案：