Question

It‟s no secret that American infrastructure is aging. Concrete(混凝土) structures, in particular, are in desperate need of repair.

Cracks (缝隙) are very common due to various chemical and physical phenomena that occur during everyday use, which can be quite harmful as they provide an easy route in for liquids and gasses and the harmful substances they might contain. But continuous repair work is difficult because it usually requires a huge amount of labor and investment. So since 2013, I‟ve been trying to figure out how these harmful cracks could heal themselves without human involvement. The idea was originally inspired by the amazing ability of the human body to heal itself of cuts, bruises and broken bones. In the same way, can we provide necessary products to concrete to fill in cracks when damage happens?

My colleagues from Binghamton University and I have found an unusual candidate to help concrete heal itself: a fungus (真菌) called Trichoderma reesei. We initially screened about 20 different species of fungi in order to find one that could stand the difficult conditions in concrete. Of all the fungi we tested, only T. reesei could survive this environment. Despite the sudden PHincrease, its spores (孢子) developed into threadlike things and grew equally well with or without concrete.

We propose including fungal spores, together with nutrients, during the initial mixing process when building a new concrete structure. When the unavoidable cracking occurs and water finds its way in, the sleeping fungal spores will start to grow. They then will work as an activator within the calcium-rich conditions of the concrete to promote precipitation (析出) of calcium carbonatecrystals. These mineral deposits can fill in the cracks. If cracks form again and environmental conditions become favorable, the spores could wake up and repeat the process.

Our research is still in the initial stage and there’s a long way to go to make self-healing concrete practical and cost-effective. But the scope of American infrastructure’s challenges makes exploring creative solutions like this worthwhile.

1.Why does the author mention the self-healing of human body?

A. To show how amazing human body is.

B. To prove everything will turn out to be fine.

C. To provide a possibility of concrete healing itself.

D. To stress that it’s unnecessary to have medicines.

2.What do we know about T. reesei?

A. It has been applied to building a new concrete.

B. It can bear the tough conditions in concrete.

C. Its spores will be useless after one repair.

D. It poses potential risks to environment.

3.What does the underlined word “this” in the last paragraph refer to?

A. The challenges of American infrastructure.    B. The research on self-healing concrete.

C. The process of cracking.    D. The promotion of spores.

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

A. The Danger of Cracks    B. The Aging of American Infrastructure

C. The Most Powerful Fungus    D. Concrete Filling Its Own Cracks

Answer

1.C

2.B

3.B

4.D

【解析】

本文是一篇说明文。本文主要讲述美国基础设施的老龄化，混凝土出现裂缝。作者和同事通过测试发现了一种真菌，能使裂缝自己愈合。作者认为虽然该项研究还是初始阶段，还有很长的路要走，但是面对美国基础设施的现状，觉得这一研究是很值得的。

1.推理判断题。根据第一段中 Since 2013,I have been trying to figure out how these harmful cracks could heal themselves without human involvenment ...when damage happens?可知，作者受人类自愈功能的灵感的激发，产生了要调查清楚混凝土缝隙在没有人类的作用下怎样自愈的，故作者提到人类自愈是为了证明混凝土缝隙有可能会自愈。故选C。

2.推理判断题。根据第三段中 Of all the fungi we tested ,only T.reesei could survive these environment可知，所有20种不同类型的真菌中，只有T.reesei能经受得住混凝土中的艰苦条件。故选B。

3.代词指代题。根据最后一段中 there is a long way to go to make self-healing concrete practical and cost-effective. But the scope of American infrastructure's challenges makes exploring creative solutions like this worthwhile可知，虽然让混凝土自愈（这一研究项目）达到实用化和有成本效益化还有很长的路要走，但是美国的大范围的基础设施老龄化，让（有创造性的）探索（此类解决办法）很值得，故可推知“this”指的是“混凝土自愈的研究”。故选B。

4.主旨大意题。本文主要讲述的是面对美国基础设施的老龄化混凝土出现裂缝，作者和同事通过测试发现了一种真菌，能使缝隙自己愈合。A项意为“缝隙的威胁”;B项意为“基础设施的老龄化”;C项意为“最强大的一种真菌”;D项意为“混凝土自愈缝隙”。故选D。