Question

You probably know that frogs hop ( 双足跳 ). But did you know that there’s a small frog in the Pacific Northwest that bellyflops（肚子先着水）? It’s called a tailed frog.

Dr.Rick Essner, who has been studying tailed frogs for the past few years, says, “ I’ve looked at thousands of jumps and have never seen them land on their feet like other frogs.” Most of the time, tailed frogs land on their stomachs and then bring their back legs in to prepare for another jump.

Essner forst noticed these frogs because of the way they swim. Other frogs kick both of their back legs at the same time. But when a tailed frog swims, it pushes first with one leg and then the other.

To try to find out why tailed frogs bellyflop, Essner and other scientists collected and filmed different kinds of frogs. They found that all of the frogs start their jumps the same way: they hold out their legs. The change comes in the landing. Tailed frogs can't move their back legs as quickly as other frogs do. Maybe they don’t need to. Tailed frogs live around water and quickly jump into the water to escape danger.

Early frogs developed around watery areas and could jump quickly into the water to escape danger. Scientists think those frogs blended in with (与…融合在一起) the green plants on the side of the rocky rivers, just like today’s tailed frogs. “Ｉwould guess that other animals would have problems detecting them, ” explains Essner. When other animals find those early frogs, the frogs could jump into the river. They didn’t need to continue hopping.

Tailed frogs and other kinds of frogs went their own ways about 200 million years ago. Tailed frogs stayed by rivers. Other kinds of frogs moved to places where new hopping skills allowed them to survive.

1. What’s special about the detailed frog ?

A. It has a long tail

B. It jumps on one foot

C. It stars its jump differently

D. It lands differently from other frogs.

2. Why do tailed frogs bellyflop?

A. They have never left the water to live .

B. They have trouble in holding out their legs

C. Their back legs can’t catch up while jumping..

D. Their front legs develop better than the back ones.

3. The underlined word “detecting” in Paragraph 5 means “______”.

A. eating B. killing

C. using D. discovering

4. When they are in danger, the detailed frogs would _________.

A. jump into the water for protection

B. hop around quickly

C. hide in the green plants near the river

D. jump into the rock

Answer 1

1.D

2.C

3.D

4.A

【解析】

试题解析：本文主要讲一种青蛙，它们着陆是用肚子；一位科学家Essner在游泳时发现了这种青蛙，然后它们拍各种照片去研究，研究它们是怎样生存的，为什么有这样一种特性。

1. did you know that there’s a small frog in the Pacific Northwest that bellyflops（肚子先着水）? It’s called a tailed frog.所以tailed frogs就是他与其他着陆的方式不一样。故选D

2. frogs can't move their back legs as quickly as other frogs do.

尾蛙的后腿不能像其他青蛙一样动作的那么快。故选C

3. frogs 和周围的植物融为了一体，所以其他的动物不会发现它。单词detect意思就洞察，发觉。A吃；B杀；C用；D发现。故选D

4.数第二段第一句Early frogs developed around watery areas and could jump quickly into the water to escape danger.早期的青蛙是在水域生长，而且可以快速的跳入水中逃生。故选A

考点：考查科普说明文。