Question

    Like most people, you have probably lost count of the number of perfect-looking shoes you have thrown away simply because the rubber soles (橡胶鞋底) are broken. In addition to the expense, it is also harmful to our environment. Now, thanks to a revolutionary self-healing 3-D printed rubber material, broken shoe soles may be a thing of the past.

The magical polymer (聚合物) is developed by the researchers at the University of Southern California’s (USC) and the University of Connecticut (UConn) . The team, led by USC Assistant Professor Qiming Wang, created it through a process called photopolymerization, which uses light to solidify the liquid used to create 3-D printed plastic. The researchers found that adding the right amount of oxidant (氧化剂) to the liquid allowed the 3-D polymer to heal (愈合) without slowing down the hardening process.

“When we gradually increase the oxidant, the self - healing behavior becomes stronger, but the photopolymerization behavior becomes weaker,” explained Wang. “There is competition between these two behaviors.”

The team, who published the findings in the journal NPG Asia Materials on February 1st,2019, state that the repair time can be reduced by increasing the room temperature. “If you just put a broken shoe on a bench at room temperature, the rubber will heal itself in six to eight hours,” Wang said. “If you apply heat at maybe 60℃, that expedites the healing process to about two hours.”

Given the material s huge potential, it is not surprising to hear that Wang and his team have been approached by several shoe-making companies eager to be the first to use the technology, which is still in the early stages. Once perfected, the scientists also hope to apply the technique to hard plastics that can be used to create self-healing toys, electronics, vehicle parts, and, if Wang has his way, even tires.

1.How do the researchers make 3-D printed plastic self- heal?

A.By changing the amount of light used.

B.By raising the temperature at which it is used.

C.By increasing the hardening speed of the liquid.

D.By adding the proper amount of oxidant to the liquid.

2.What can be inferred from the text?

A.The creation of 3-D printed plastic doesn’t need light.

B.The surrounding temperature determines the speed of healing.

C.Many shoe making companies got the right to use the technology.

D.Throwing away broken shoe soles has been a thing of the past.

3.What does the underlined word “expedites” mean?

A.Strengthens. B.Delays. C.Accelerates. D.Worsens.

4.Which of the following can be the best title of the text?

A.Self - healing shoes may be in our future.

B.3-D printing technology makes a difference.

C.Self - healing technology will serve many fields.

D.A revolution of rubber soles has changed our life.

Answer

1.D

2.B

3.C

4.A

【解析】

这是一篇说明文。主要说明了一种新的产品：会自我修复的三维打印鞋底。研究人员发现，在液体中加入适量的氧化剂可以使3D聚合物在不减慢硬化过程的情况下愈合，且周围的温度决定了愈合的速度。这意味着自愈合鞋可能会出现在我们的未来。

1.细节理解题。根据第二段中The researchers found that adding the right amount of oxidant (氧化剂) to the liquid allowed the 3-D polymer to heal (愈合) without slowing down the hardening process.可知研究人员发现，在液体中加入适量的氧化剂可以使3D聚合物在不减慢硬化过程的情况下愈合。由此可知，研究人员通过向液体中加入适量的氧化剂使3D打印塑料自愈。故选D。

2.推理判断题。根据第四段中“If you just put a broken shoe on a bench at room temperature, the rubber will heal itself in six to eight hours,” Wang said. “If you apply heat at maybe 60℃, that expedites the healing process to about two hours.”可知王说:“如果你把一只破鞋子放在室温下的凳子上，橡胶会在6到8小时内自行愈合。”“如果你在60摄氏度的温度下加热，愈合过程会加快到大约两个小时。”由此可推知周围的温度决定了愈合的速度。故选B。

3.词义猜测题。根据上文If you just put a broken shoe on a bench at room temperature, the rubber will heal itself in six to eight hours以及后文the healing process to about two hours.可知如果你只是把破鞋子放在室温下的凳子上，橡胶会在6到8小时内自行愈合，如果你在60摄氏度的温度下加热，那样expedites愈合过程到两个小时左右。时间缩短了，自然是加快了愈合过程。可知划线单词意思为“加快，加速”。故选C。

4.主旨大意题。根据文章第一段中Now, thanks to a revolutionary self-healing 3-D printed rubber material, broken shoe soles may be a thing of the past.可知现在，由于一种革命性的自修复3D打印橡胶材料，破损的鞋底可能成为历史。结合文章主要内容为说明这种可以自我修复的3D打印鞋底。故A选项“自愈合鞋可能会出现在我们的未来”符合文章标题。故选A。