Question

You probably know that frogs hop ( 雙足跳 ). But did you know that there’s a small frog in the Pacific Northwest that bellyflops（肚子先著水）? 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 (與…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】

試題解析：本文主要講一種青蛙，它們著陸是用肚子；一位科學(xué)家Essner在游泳時發(fā)現(xiàn)了這種青蛙，然后它們拍各種照片去研究，研究它們是怎樣生存的，為什么有這樣一種特性。

1. did you know that there’s a small frog in the Pacific Northwest that bellyflops（肚子先著水）? It’s called a tailed frog.所以tailed frogs就是他與其他著陸的方式不一樣。故選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樣動作的那么快。故選C

3. frogs 和周圍的植物融為了一體，所以其他的動物不會發(fā)現(xiàn)它。單詞detect意思就洞察，發(fā)覺。A吃；B殺；C用；D發(fā)現(xiàn)。故選D

4.數(shù)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長，而且可以快速的跳入水中逃生。故選A

考點：考查科普說明文。