Question

Monarch butterflies (黑脉金斑蝶) are a common summer sight in the northern United States and Canada. These large orange and black insects (昆虫) brighten parks and gardens as they fly lightly among the flowers. What makes monarchs particularly interesting is that they migrate (迁飞) —all the way to California or Mexico and back. They are thought to be the only insect that does this.

    Every year in the late summer monarchs begin their journey to the south. Those heading for Mexico go first for the Louisiana-Mississippi area, and then fly across the Gulf of Mexico into Texas. Once in Mexico, they settle themselves in one of about fifteen places in a mountain forest filled with fir trees. Each place provides a winter home for millions of monarchs. The butterflies are so many that they often cover entire trees. When spring comes, they begin their long journey north.

    The question is often asked whether every butterfly makes the round-trip journey every year. And the answer is no. The average monarch lives about nine months. So one flying north might lay eggs in Louisiana and then die. The eggs of that generation may be found in Kentucky; the eggs of the next generation may end up in Wisconsin or Michigan. The last generation of the season, about the fourth, will make their way back to Mexico and restart the journey.

    Scientists learn about monarchs’ migration by catching and making marks on the insects. By re-catching a monarch with such a mark and noticing where it came from, the next scientist can get to know things like the butterfly’s age and its routing (路线).

1. One of the places where monarchs spend the winter is _____.

A. the Gulf of Mexico

B. an area in Mississippi

C. a forest in Mexico

D. a plain in Texas

2. The routing of monarchs’ migration can be learned _______.

A. by examining the marks made on them

B. by collecting their eggs in the mountains

C. by comparing their different ages

D. by counting the dead ones in the forests

3. What is the subject discussed in the passage?

A. Migration of monarchs.

B. Scientists’ interest in monarchs.

C. Winter home of monarchs.

D. Life and death of monarchs.

 

Answer 1

答案：CAA
解析：

1. 细节判断题。原文第一节中“…they migrate-all the way to California or Mexico-and back”,以及原文第二节“Every year in the late summer…Those heading for Mexico go first for the Louisiana-Mississippi area, then fly across the Gulf of Mexico into Texas. Once in Mexico, they settle themselves in one of about fifteen places… Each place provides a winter home for millions of monarchs. ”中，可以得知，选项A、B、D所指的地点均为monarchs南迁中途经的地区。而文中One in Mexico, they settle themselves….Each place provides a winter home for…，则表明C是正确选项。 2. 细节理解题。原文最后一小节：“Scientists learn about monarchs’ migration by catching and making marks on the insects. By recatching （=catch again） a monarch with such a mark and noticing where it came from (=examining its routing),the next scientist can get to know things like the butterfly’s age and its outing.”十分清楚地表明黑脉金斑蝶迁飞路线是通过给它们身上所作的记号中得知。显然A项是惟一正确的答案。 3. 归纳综合题。全篇短文四个段落均围绕黑脉金斑蝶所具有的迁飞生活习性展开的。显然，A项是本文陈述的主题。