believe that climate change, ecessive hunting by humans and the spread of other animals into mammoth feeding grounds were influential factors.
28. The underlined word \
A. figure head B. female leader C eperienced animal D. mature mammoth 29. Why do the majority of mammoth fossils come from male animals? A. Scientists find it easier to study male fossilied bones. B. There were more male mammoths in comparison to females
C Male mammoths were better able to adapt to the changing circumstances. D. Male mammoths more frequently died in places where fossils could form. 30. Which of the following is suggested as a reason for mammoths dying out? A. The increasing competition for food. B. The cooling of the earth's temperature.
C. The disappearance of male mammoths. D The risy behaviour of younger mammoths.
31. What is the tet type of the passage?
A. A newspaper article. B. An academic essay. C. A historical description. D. A science fiction story.
It?s no secret that American infrastructure is aging. Concrete(混凝土) structures, in particular, are in desperate need of repair.
Cracs (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 wor 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 cracs could heal themselves without human involvement. The idea was originally inspired by the amaing ability of the human body to heal itself of cuts, bruises and broen bones. In the same way, can we provide necessary products to concrete to fill in cracs 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 threadlie things and grew equally well with or without concrete.
We propose including fungal spores, together with nutrients, during the initial miing process when building a new concrete structure. When the unavoidable cracing occurs and water finds its way in, the sleeping fungal spores will start to grow. They then will wor 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 cracs. If cracs form again and environmental conditions become favorable, the spores could wae up and repeat the process.
Our research is still in the initial stage and there’s a long way to go to mae self-healing concrete practical and cost-effective. But the scope of American infrastructure’s challenges maes eploring creative solutions lie this worthwhile. 32. Why does the author mention the self-healing of human body? A.To show how amaing 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. 33. What do we now 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 riss to environment.
34. 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 cracing. D.The promotion of spores. 35. Which of the following can be the best title for the tet?
A.The Danger of Cracs B.The Aging of American Infrastructure C.The Most Powerful Fungus D.Concrete Filling Its Own Cracs 第二节（共5小题；每小题2分，满分10分）
How to overcome challenges in your life
We all face tough and difficult challenges in life. To overcome challenges you need to have that “never quit” attitude in life. If you develop it, you’ll overcome quite a bit.
Motivate yourself. Say “YES, I CAN.” The challenge should bring out the best of you in this situation. Slow it down, and thin that process through. 36 If you develop that mindset (心态), you’ll get it done.
37 Remain calm when you’re facing serious troubles and problems in life. You have to recollect yourself, and calm down. You can’t solve problems when you’re panicing. Tae a deep breath, rela, and slow it down. Thin things through calmly.
Let failure and fear fuel you in a positive way. Everyone fails at times. If you fail the first, second, or third time, don’t give up. 38 Learn what made you fail at overcoming these challenges.
Simplify the challenge you’re facing. Mae the challenge easier than it is. 39 As you get through each step, you develop more confidence and you believe you can get it done, and then you will.
Stay positive and confident. 40 You have to find out all the ways you can use to overcome it, and put them to full use with all your effort. It’s our own mental stability that’s the difficult part. When you do it mentally, you’ll actually be able to do it. A. Stay calm and cool headed. B. Thin the best, not the worst. C. Start by breaing it down into steps.
D. To overcome a challenge, you have to believe you can really do it. E. Most people will avoid any challenge, because they’re scared of failing. F. Develop that confidence in saying there’s no way you’re going to fail at this. G. Pic yourself up, and learn from why you’ve failed, and move on in a positive direction.
In my second year of high school, I met the anthropology (人类学) teacher, Mr. Croft. I didn’t now anything about anthropology, so I never signed up for Mr. Croft’s class. 41, this didn’t stop him from positively 42 my life.
Mr. Croft was a 43 twenty-four hours a day — after school, before school, and in and out of his 44 . Mr. Croft inspired and taught every student at East High, 45 me. He often 46 me to become all I could possibly be.
How could I possibly 47 Mr. Croft? After I graduated from high school, I had an opportunity to 48 football for thirteen-year-olds. To get a feel for the boys’ 49 , I had each of them run out for a 50 . I wanted to see who could run, catch and throw so I could 51 a team in my mind.
Two days into practice, a tall id appeared on the field. He got in 52 , and when he ran out for a pass, I threw the ball. It hit him square in the 53 . He piced up the 54 and ran it bac to me. It came time for his second pass and I 55 him in the head again. With his nose bleeding and his lip swelling, he 56 the ball, raced it bac to me, and got bac in line.
Later I got to now that he was the son of my anthropology teacher, Tommy Croft. I was 57 . He said, “I’m here because I want to play football. And I promise 58 you’ll help me, I now I can do it!”