Question

【題目】 You are walking over the tan-colored（棕褐色的）sand of the empty desert when a rattlesnake appears out of the sand in front of you. Luckily it had warned you of its presence. Imagine if that same snake were moved to a green leafy rainforest. The colors that helped the snake blend into（融合）the desert would make it stand out against the green environment.

This just goes to show you that camouflage（保護(hù)色）doesn't work everywhere. Let's take a look at one animal species that is famous for changing over time to stay camouflaged: the peppered moth. Moth collectors in England noted that most peppered moths collected in the early 1800s were light gray peppered with bits of black. Many years later most of the moths collected were almost completely black. What could have caused the more common light colored moth to become rare?

During the 1800s, Europe and America experienced the Industrial Revolution. One of the new fuel sources that were heavily used during this time period was coal. As the trees darkened with soot（煤煙）, the light-colored moths were easier to see. They were eaten by birds more and more, while the rare dark colored moths blended in better on the darker trees. This made them have a higher survival rate and thus they were more likely to pass their dark colored genes onto their children. Over time, the dark colored moths became the more common of the two color forms. Natural selection favored the dark moths, so they were more successful after the trees changed.

Sound a little hard to believe? Well, more changes have come about since these conditions started to reverse（轉(zhuǎn)變）, starting in the 1950s. Then, a Clean Air Act was introduced. Since that time, technology and cleaner burning fuels have started to decrease pollution in the areas where the peppered moth lives. The black soot no longer settles on the trees. As expected, the light peppered moth has recently been more common in the population. This is because it is better camouflaged.

【1】What do we know about the rattlesnake in a desert?

A.It almost has no enemies.

B.It attacks travelers often.

C.It stands out against the environment.

D.It is good at making its presence unknown.

【2】The underlined word "This" in Paragraph 3 refers " "

A.the soot-darkened tree

B.the Industrial Revolution

C.dark-colored moths staying camouflaged

D.light-colored moths facing more enemies

【3】What did the Clean Air Act bring about?

A.Damage to local ecology.B.More observations of moths.

C.An increase in the variety of moth species.D.A decrease in the number of dark-colored moths.

【4】What is the text mainly about?

A.Camouflage in the animal world.B.The battle between two moth species.

C.The influence of the Industrial Revolution.D.An excellent example of environmental adaptation.

Answer 1

【答案】

【1】D

【2】C

【3】D

【4】D

【解析】

本文是說明文。文章介紹了擅用保護(hù)色來偽裝自己的胡椒蛾。

【1】

細(xì)節(jié)理解題。根據(jù)第一段最后一句：The colors that helped the snake blend into the desert（顏色幫助這種蛇融入了沙漠。）可知，沙漠中的響尾蛇善于讓自己的存在不為人所知。故選D。

【2】

詞義猜測題。由劃線詞前一句中的while the rare dark colored moths blended in better on the darker trees而稀有的深色蛾則更好地融合在深色的樹上�？芍�，This此處指代“深色胡椒蛾能更好地與周圍環(huán)境相融合”的情況。選項(xiàng)C“深色胡椒蛾進(jìn)行偽裝”符合題意。故選C。

【3】

推理判斷題。根據(jù)最后一段中的Then, a Clean Air Act… the light peppered moth has recently been more common in the population. 然后，《清潔空氣法案》被提出。 從那時(shí)起，科技和清潔燃料已經(jīng)開始減少胡椒蛾生活的地區(qū)的污染。 黑色的煙塵不再落在樹上。 正如所料，淺色胡椒蛾最近在種群中更為常見�？芍�，《清潔空氣法案》的落地意味著深色胡椒蛾不再能利用保護(hù)色偽裝自己，其數(shù)量銳減。選項(xiàng)D符合題意。故選D。

【4】

主旨大意題。第二段Let's take a look at one animal species that is famous for changing over time to stay camouflaged: the peppered moth.（讓我們來看看一種動(dòng)物，它以隨著時(shí)間的變化而保持偽裝而聞名:胡椒蛾。）是全文的主題句，結(jié)合全文內(nèi)容，可知這篇文章介紹了胡椒蛾為適應(yīng)環(huán)境變化所做出的改變——其身體的顏色隨著所棲息的樹木的顏色的變化而變化。D項(xiàng)“一個(gè)很好的適應(yīng)環(huán)境的例子”最能概括本文主旨。故選D。