题目内容
Almost anyone who has read a travel brochure about Africa has heard of elephants getting drunk from the fruit of the marula tree. It is said that elephants can get drunk by eating the fermented (发酵) fruit rotting on the ground. Books have even been written to prove the truth of the phenomenon.
But a study published in the journal Physiological and Biochemical Zoology tells a very different story.
Steve Morris, a biologist at the University of Bristol in England and an author of the study, says there is nothing in the biology of either the African elephant or the marula fruit to support the stories. Morris says, “ people just want to believe in drunken elephants.”
The marula tree, a member of the same family as the mango, grows widely in Africa. Its sweet, yellow fruit is used for making jam, wine and beer. “The first mistake of the drunken-elephant theory is that it’s unlikely that an elephant would eat the fruit if it were rotten, ” Morris says. “Elephants eat the fruit right off the tree, not when it’s rotten on the ground, ” he explains.
Other experts add that if an elephant were to eat the fruit on the ground, it wouldn’t wait for the fruit to ferment. Michelle Gadd, an African wildlife specialist, says that elephants and many other animals, including birds and monkeys, are too fond of marula fruit to let it rot.
If fermented fruit on the ground is out of the question, so is the notion that the fruit could ferment in the stomach of elephants, according to the study authors. Food takes between 12 and 46 hours to pass through an elephant’s digestive system, the authors point out, which is not enough for the fruit to ferment.
Supposing that this happened, it’s still highly improbable that the food would produce enough alcohol to make an elephant drunk. Through calculations of body weight, elephant digestion rates, and other factors, the authors conclude 
that it would take about 1.9 litres of ethanol(乙醇) to make an elephant drunk.
56. We can learn from the passage that ________.
A. it is not easy to find marula fruit in the wild in Africa
B. African elephants don’t like to eat marula fruit at all
C. marula fruit can be made into food or drink consumed by people
D. birds and monkeys in Africa like to eat rotten marula fruit
57. According to Paragraph 6, marula fruit is likely to ferment ________.
A. in about 12 hours B. in about 34 hours
C. between 12 and 46 hours D. in more than 46 hours
58. According to Mr. Morris, which of the following is TRUE?
A. Elephants just eat the fruit right off the tree.
B. Elephants will not eat the fruit which is rotten.
C. The marula tree and the mango belong to different families.
D. There are several connections b
etween Elephants and the marula fruit.
59 . What does the underlined word “this” in the last paragraph probably refer to ?
A. Elephants getting drunk.
B. Marula fruit fermenting in elephants’ stomachs.
C. Elephants eating rotten marula fruit.
D. Elephants eating marula trees directly.
CDBB
天天向上一本好卷系列答案
小学生10分钟应用题系列答案You never see him, but they're with you every time you fly. They record where you are going, how fast you're traveling and whether everything on your airplane is functioning normally. Their ability to endure almost any disaster makes them seem like something out of a comic book. They're known as the black box.
When planes fall from the sky, as a Yemeni airliner did on its way to Comoros Islands in the India ocean on June 30, 2009, the black box is the best bet for identifying what went wrong. So when a French submarine (潜水艇) detected the box's homing signal five days later, the discovery marked a huge step toward determining the cause of a tragedy in which 152 passengers were killed.
In 1958, Australian scientist David Warren developed a flight-memory recorder that would track basic information like altitude and direction. That was the first mode for a black box, which became a requirement on all U.S. commercial flights by 1960. Early models often failed to withstand crashes, however, so in 1965 the box was completely redesigned and moved to the rear of the plane – the area least subject to impact – from its original position in the landing wells (起落架舱). The same year, the Federal Aviation Authority required that the boxes, which were never actually black, be painted orange or yellow to aid visibility.
Modern airplanes have two black boxes: a voice recorder, which tracks pilots' conversations, and a flight-data recorder, which monitors fuel levels, engine noises and other operating functions that help investigators reconstruct the aircraft's final moments. Placed in an insulated (隔绝的) case and surrounded by a quarter-inch-thick panels of stainless steel, the boxes can stand massive force and temperatures up to 2,000℉. When submerged, they're also able to emit signals from depths of 20,000 ft. Experts believe the boxes from Air France Flight 447, which crashed near Brazil on June 1,2009, are in water nearly that deep, but statistics say they're still likely to turn up. In the approximately 20 deep-sea crashes over the past 30 years, only one plane's black boxes were never recovered.
【小题1】What does the author say about the black box?
| A．It is an indispensable device on an airplane. |
| B．The idea for its design comes from a comic book. |
| C．Its ability to avoid disasters is incredible. |
| D．It ensures the normal functioning of an airplane. |
| A．witness | B．experience | C．resist | D．ensure |
| A．New materials became available by that time. |
| B．Too much space was needed for its installation. |
| C．The early models didn't provide the needed data. |
| D．The early models often got damaged in the crash. |
| A．There is an urgent need for them to be reconstructed. |
| B．There is still a good chance of their being recovered. |
| C．They have stopped sending homing signals. |
| D．They were destroyed somewhere near Brazil. |
You never see him, but they're with you every time you fly. They record where you are going, how fast you're traveling and whether everything on your airplane is functioning normally. Their ability to endure almost any disaster makes them seem like something out of a comic book. They're known as the black box.
When planes fall from the sky, as a Yemeni airliner did on its way to Comoros Islands in the India ocean on June 30, 2009, the black box is the best bet for identifying what went wrong. So when a French submarine (潜水艇) detected the box's homing signal five days later, the discovery marked a huge step toward determining the cause of a tragedy in which 152 passengers were killed.
In 1958, Australian scientist David Warren developed a flight-memory recorder that would track basic information like altitude and direction. That was the first mode for a black box, which became a requirement on all U.S. commercial flights by 1960. Early models often failed to withstand crashes, however, so in 1965 the box was completely redesigned and moved to the rear of the plane – the area least subject to impact – from its original position in the landing wells (起落架舱). The same year, the Federal Aviation Authority required that the boxes, which were never actually black, be painted orange or yellow to aid visibility.
Modern airplanes have two black boxes: a voice recorder, which tracks pilots' conversations, and a flight-data recorder, which monitors fuel levels, engine noises and other operating functions that help investigators reconstruct the aircraft's final moments. Placed in an insulated (隔绝的) case and surrounded by a quarter-inch-thick panels of stainless steel, the boxes can stand massive force and temperatures up to 2,000℉. When submerged, they're also able to emit signals from depths of 20,000 ft. Experts believe the boxes from Air France Flight 447, which crashed near Brazil on June 1,2009, are in water nearly that deep, but statistics say they're still likely to turn up. In the approximately 20 deep-sea crashes over the past 30 years, only one plane's black boxes were never recovered.
【小题1】What does the author say about the black box?
| A．It is an indispensable device on an airplane. |
| B．The idea for its design comes from a comic book. |
| C．Its ability to avoid disasters is incredible. |
| D．It ensures the normal functioning of an airplane. |
| A．witness | B．experience | C．resist | D．ensure |
| A．New materials became available by that time |
| B．Too much space was needed for its installation. |
| C．The early models didn't provide the needed data. |
| D．The early models often got damaged in the crash. |
| A．There is an urgent need for them to be reconstructed. |
| B．There is still a good chance of their being recovered. |
| C．They have stopped sending homing signals. |
| D．They were destroyed somewhere near Brazil. |