Question

Monarch butterflies(帝王蝶) from the eastern part of North America make the most amazing journey in the insect world. Each year, this tiny creature(生物) travels up to 3,000 miles(4,800 kilometers) to its winter home in central Mexico(墨西哥). How can it fly so far? And what is the purpose of its long and dangerous trip? Scientists still don’t have an explanation.

The length of the butterflies’ trip is only one part of the mystery. The other amazing thing is that the butterflies always return to the same place in central Mexico. How do the butterflies find their way back to the same place? This is an interesting question because only every fourth generation(代) makes the trip south. In other words, the butterfly that travels to Mexico this year is the great-great-grandchild of the butterfly that traveled there last year.

Each year, four generations of a Monarch butterfly family are born. Each generation of the family has a very different life. The first generation of Monarchs is born in the south in late April. It slowly moves north, reproduces, and then dies. On the trip north, two more generations are born, reproduce, and die. Each of these generations of butterflies lives for only two to five weeks. In the fall, the fourth generation of butterflies is born. Compared to its parents, this generation has a long life. It lives for about eight months. This generation of butterflies makes the amazing journey to the winter home of its great-great-grandparents. The butterflies spend the winter there, and in the spring they reproduce and then die. Their children will be the first generation of the next circle. How amazing it is!

1.From the passage we know that monarch butterflies ________.

A.spend their winter in North America

B.are small but can fly quite a long way

C.travel to central Mexico to reproduce

2.There are ________ mysteries about monarch butterflies’ journey.

A.two B.three C.four

3.The last paragraph is mainly about ________.

A.why Monarch butterflies fly from north to south

B.how Monarch butterflies make the amazing trip

C.when each generation of butterflies reproduce

4.According to the article, which of the following is NOT TRUE?

A.Two of the generations are born on the trip back to south.

B.Only the fourth generation can live through the whole winter.

C.The first generation of Monarchs is born in the south in spring.

5.We can read this passage on the ________ part of a magazine.

A.sports and health B.science and technology C.environment and nature

Answer

1.B

2.A

3.B

4.A

5.C

【解析】

文章大意：北美洲东部的帝王蝶每年飞行四千八百公里到它们位于墨西哥中部的冬季的家，而且总能返回相同的地方，且每四代帝王蝶能完成南飞的行程一次。

1.细节理解题。根据第1段中“Each year, this tiny creature travels up to 3,000 miles(4,800 kilometers) to its winter home in central Mexico.”可知帝王蝶极小，但却能飞行很远的路。故选B。

2.细节理解题。根据第2段中“The length of the butterflies’ trip is only one part of the mystery. The other amazing thing is that the butterflies always return to the same place in central Mexico.”可知旅行距离长是其中一件神秘的事，另一件神秘的事情是它们总能到达墨西哥中部的同一个地方，一共两个谜团。故选A。

3.段落大意题。根据最后一段中从第一代帝王蝶四月末在南方出生讲到往北的旅程中两代帝王蝶出生病死亡，再到最后一代帝王蝶飞到冬季的家并产下下一代开始下一个循环，可知这一段主要讲帝王蝶如何完成这令人惊奇的旅行。故选B。

4.细节理解题。根据最后一段中“On the trip north, two more generations are born, reproduce, and die.”可知两待帝王蝶在北行的旅程中出生、生产和死亡，并不是在南归的过程中，A项错误；根据最后一段中“In the fall, the fourth generation of butterflies is born. … The butterflies spend the winter there, and in the spring they reproduce and then die.”可知只有第四代能活过整个冬天，B项正确；根据最后一段中“The first generation of Monarchs is born in the south in late April.”可知第一代帝王蝶出生于南方的春天，C项正确。故选A。

5.推理判断题。本文主要介绍了帝王蝶的相关内容，是关于动物的，应该会出现在杂志的“环境与自然”部分。故选C。