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Scientists are confused about two newly discovered stars. One was announced in 2022 in Nature. They send out long pulses of radio waves(长脉冲射电波) about every 20 minutes. They move much more slowly and have characteristics astronomers cannot explain. “We are all still quite amazed,” says astronomer Natasha Hurley-Walker.
The mystery began in 2021, when Hurley-Walker and her colleagues discovered a slowly repeating radio pulse. It shone for three months, but later its activity died down. In a 2022 paper, scientists suggested it could be a magnetar(磁星). But GLEAM-X J162759.5-523504.3 sent pulses every 18 minutes instead of every few seconds like known magnetars.
It also had no X-ray signal, which does not fit magnetar theories. Its magnetic field(磁场) was much stronger than seen before. So scientists began looking for similar objects. In June 2022, they observed the sky every three nights and soon found another object pulsing every 21 minutes.
At first, it looked similar to the first one. But after studying more data, GPM J1839-10 seemed more confusing(令人困惑的). Its signal had existed for decades.
Researchers think the two objects may be the same kind. But why does one flash for three months and the other for 33 years?
(
A. They were made public in Nature in 2022.
B. They move at the slowest speed of all known stars.
C. They send out short radio waves every 20 minutes.
D. They are unlike the stars astronomers have seen before.
(
A. Every 18 minutes.
B. Every 20 minutes.
C. Every 21 minutes.
D. Every few seconds.
(
A. Strange characteristics of the first star.
B. The assumption(假设) of the magnetar theories.
C. Radio waves research project.
D. The government's guidance programme.
(
A. None of his business.
B. Confused.
C. Nagative.
D. Active.
D
Scientists are confused about two newly discovered stars. One was announced in 2022 in Nature. They send out long pulses of radio waves(长脉冲射电波) about every 20 minutes. They move much more slowly and have characteristics astronomers cannot explain. “We are all still quite amazed,” says astronomer Natasha Hurley-Walker.
The mystery began in 2021, when Hurley-Walker and her colleagues discovered a slowly repeating radio pulse. It shone for three months, but later its activity died down. In a 2022 paper, scientists suggested it could be a magnetar(磁星). But GLEAM-X J162759.5-523504.3 sent pulses every 18 minutes instead of every few seconds like known magnetars.
It also had no X-ray signal, which does not fit magnetar theories. Its magnetic field(磁场) was much stronger than seen before. So scientists began looking for similar objects. In June 2022, they observed the sky every three nights and soon found another object pulsing every 21 minutes.
At first, it looked similar to the first one. But after studying more data, GPM J1839-10 seemed more confusing(令人困惑的). Its signal had existed for decades.
Researchers think the two objects may be the same kind. But why does one flash for three months and the other for 33 years?
(
D
)46. What can be learnt about the two newly discovered stars?A. They were made public in Nature in 2022.
B. They move at the slowest speed of all known stars.
C. They send out short radio waves every 20 minutes.
D. They are unlike the stars astronomers have seen before.
(
D
)47. How often do known magnetars send out a pulse?A. Every 18 minutes.
B. Every 20 minutes.
C. Every 21 minutes.
D. Every few seconds.
(
A
)48. What drove scientists to look for the second star?A. Strange characteristics of the first star.
B. The assumption(假设) of the magnetar theories.
C. Radio waves research project.
D. The government's guidance programme.
(
B
)49. What's Hurley-Walker's reaction to the result of their observation?A. None of his business.
B. Confused.
C. Nagative.
D. Active.
D
答案
46. D 47. D 48. A 49. B
解析
【分析】
做这类英语阅读理解题，需先通读原文把握主旨，再针对每个小题的题干关键词，回到原文定位对应信息，逐一比对选项排除错误答案，选出正确选项。具体来看：46题需找两颗新恒星的共同特征，47题找已知磁星的脉冲频率，48题找科学家发现第二颗恒星的原因，49题找Hurley-Walker的反应，均需精准定位原文细节。
【解析】
46题：根据原文第一段“have characteristics astronomers cannot explain”可知，这两颗恒星有天文学家无法解释的特征，与之前见过的恒星不同，故D正确；A选项错误，仅第一颗恒星是2022年在《自然》杂志公布；B选项“最慢速度”原文未提及；C选项错误，原文是“long pulses of radio waves”而非短射电波。
47题：根据原文第二段“instead of every few seconds like known magnetars”可知，已知磁星的脉冲频率是每几秒，故D正确。
48题：根据原文第二段和第三段，第一颗恒星的特征（脉冲18分钟、无X射线信号、磁场更强）不符合磁星理论，因此科学家开始寻找类似天体，进而发现第二颗恒星，故A正确；B选项磁星理论的假设不是找第二颗的原因；C、D选项原文未提及。
49题：根据原文第一段“Scientists are confused about two newly discovered stars”以及Hurley-Walker的表述，可知她对观测结果的反应是困惑，故B正确。
【答案】
46.D 47.D 48.A 49.B
【知识点】
英语阅读理解（细节理解）、英语阅读理解（推理判断）
【点评】
本文为科技说明文，围绕两颗新发现的特殊恒星展开，主要考查学生对原文细节信息的定位与理解能力，题型以细节题为主，难度适中，仔细阅读原文对应内容即可准确作答。
【难度系数】
0.6
做这类英语阅读理解题，需先通读原文把握主旨，再针对每个小题的题干关键词，回到原文定位对应信息，逐一比对选项排除错误答案，选出正确选项。具体来看：46题需找两颗新恒星的共同特征，47题找已知磁星的脉冲频率，48题找科学家发现第二颗恒星的原因，49题找Hurley-Walker的反应，均需精准定位原文细节。
【解析】
46题：根据原文第一段“have characteristics astronomers cannot explain”可知，这两颗恒星有天文学家无法解释的特征，与之前见过的恒星不同，故D正确；A选项错误，仅第一颗恒星是2022年在《自然》杂志公布；B选项“最慢速度”原文未提及；C选项错误，原文是“long pulses of radio waves”而非短射电波。
47题：根据原文第二段“instead of every few seconds like known magnetars”可知，已知磁星的脉冲频率是每几秒，故D正确。
48题：根据原文第二段和第三段，第一颗恒星的特征（脉冲18分钟、无X射线信号、磁场更强）不符合磁星理论，因此科学家开始寻找类似天体，进而发现第二颗恒星，故A正确；B选项磁星理论的假设不是找第二颗的原因；C、D选项原文未提及。
49题：根据原文第一段“Scientists are confused about two newly discovered stars”以及Hurley-Walker的表述，可知她对观测结果的反应是困惑，故B正确。
【答案】
46.D 47.D 48.A 49.B
【知识点】
英语阅读理解（细节理解）、英语阅读理解（推理判断）
【点评】
本文为科技说明文，围绕两颗新发现的特殊恒星展开，主要考查学生对原文细节信息的定位与理解能力，题型以细节题为主，难度适中，仔细阅读原文对应内容即可准确作答。
【难度系数】
0.6
