A
(2020·陕西部分学校摸底)Three boys were enjoying themselves in their hometown of Bovina, Mississippi. However, their lives were turned upside down when they discovered the jawbone of a Mastodon(乳齿象)．
Brothers Shawn and Caid Sellers and their cousin Michael Mahalitc found the prehistoric bone in a piece of earth that was recently plowed. “I thought it was a log，” Caid said. “I tried to pick it up and it was really heavy and I saw teeth on it.” The bone weighed about 50 pounds. They eventually got the bone to their home and fitted it in their bathtub, but it took their collective strength, might and a golf cart, to carry the large Mastodon bone.
“They didn’t expect to find that，” Michael’s mom said. “Now they believe that they will be more aware of their surroundings and what they’re digging up when they are digging and playing.”
“We’ve gotten a lot of petrified(石化的) wood and Civil War relics from the area and that’s what I thought it was，” the brothers’ mother said. “This is our first set of teeth we’ve found. So we thought it was their imagination. We were quite surprised to see that it was not their imagination.”
They were exploring near the brothers’ home. It’s surprising that they saw what they thought resembled a fossil. It was the curator of paleontology(古生物学负责人) of the Mississippi Museum of Natural Science, George Phillips, who first identified the bone as a “very mature individual”．
The Mastodon was a mammal who lived during the prehistoric times. They had long tusks and trunks, like elephants. They were clearly different from their modern day counterparts, as well as woolly mammoths(猛犸)．
【解题导语】 美国密西西比州的三个男孩在玩耍的时候无意中发现了乳齿象的下颌骨，起初他们并不知道这是史前动物的遗骸。他们发现的遗骸对史前生物的研究有一定的促进作用。
1．How did they find the jawbone of a Mastodon?
A．With great efforts. B．By chance.
C．Instructed by an expert. D．Through imagination.
B 解析：细节理解题。根据第一段“Three boys were enjoying themselves...discovered the jawbone of a Mastodon(乳齿象)．”可知，他们是在玩耍的时候无意中发现乳齿象的下颌骨的。
2．The discovery of the jawbone of a Mastodon is important mainly because it ________．
A．helps people to know more about the Civil War
B．teaches kids to be more aware of their surroundings
C．promotes the research on more prehistoric creatures
D．attracts the Mississippi Museum of Natural Science
C 解析：推理判断题。根据倒数第二段中的“who first identified the bone as a ‘very mature individual’”并结合倒数第一段可知，乳齿象下颌骨的发现可以促进对史前生物的研究。
3．Which of the following can be the best title for the article?
A．Prehistoric Bones Recently Found in Mississippi
B．Not Petrified Wood nor Civil War Relics
C．First Identifying Bone as a “Very Mature Individual”
D．Unexpectedly Discovering Mastodon Jawbone
D 解析：标题归纳题。根据第一段并结合文章其他内容可知，美国密西西比州的三个男孩在玩耍的时候无意中发现了乳齿象的下颌骨，起初他们并不知道这是史前动物的遗骸，他们发现的遗骸对史前生物的研究有一定的促进作用，故D项最适合作文章标题。
