Question

Scientists in Israel have discovered a new way to test for water pollution by “l(fā)istening” to what the plants growing in water have to say.
By shining a laser beam (激光束) on the tiny pieces of algae floating in the water，the researchers said they hear sound waves that tell them the type and amount of contamination (致污物) in the water.
“It is a red light，telling us that something is beginning to go wrong with the quality of water，” said Zvy Dubinsky，an aquatic biologist at Israel’s Bar Ilan University.“Algae is the first thing to be affected by a change in water quality.”“The secret，” he said，“is to measure the rate of photosynthesis (光合作用) in the algae，meaning the plant’s ability to transform light into energy.” During photosynthesis，plants also release oxygen into the air.
Dubinsky’s technique is easy to perform because of the over­abundance of algae in the planet’s water.Most of the oxygen in the atmosphere comes from algae.A prototype tester that occupies about one square meter of a laboratory desktop，shoots a laser beam at water samples to stimulate photosynthesis in the algae.But not all of the laser’s heat is used.Depending on the condition of the algae and the rate of photosynthesis，some of the heat is shot back into the water，creating sound waves，Dubinsky said.With a special underwater microphone，researchers are able to analyze the strength of the sound waves and determine the health of the algae and the condition of the surrounding water.
“Algae suffering from lead poisoning，like waste discharged from battery and paint manufacturing plants，will produce a different sound than those suffering from lack of iron or exposure to other toxins，” said researcher Yulia Pinchasov.She said that testing algae photosynthesis can determine water quality more accurately and easily than labor­intensive methods now used like chemical and radioactive carbon testing.
小題1:The underlined word “algae” in Paragraph 2 probably refers to a kind of________.

A．instrument	B．plant
C．wood	D．pollutant

小題2:Why is the algae tested?

A．Because it floats on the water.

B．Because it can have photosynthesis.

C．Because it is the first to be polluted.

D．Because it can produce different sounds.

小題3:We can infer from the passage that________.

A．a(chǎn)lgae can produce a loud sound when polluted

B．a(chǎn)lgae can die easily from pollution

C．photosynthesis of the algae can only be caused by sunlight

D．photosynthesis of the algae is related to water quality

小題4:What would be the best title for the passage?

A．Scientists Listen to Plants to Find Water Pollution

B．A Prototype Tester Is Used to Determine Water Pollution

C．The Importance of Photosynthesis of the Algae

D．The Problem of Chemical and Radioactive Carbon Testing

Answer 1

小題1:B
小題2:C
小題3:D
小題4:A

小題1:　B
解析　詞義猜測題。由文章第一句中的“what the plants”及第三段倒數(shù)第二句中“meaning the plant’s ability to transform light into energy”可推出，algae是一種植物，因為只有植物才能進行光合作用。
小題2:　C
解析　細節(jié)理解題。由文章第三段第二句可知，藻類是水中最先受到污染的植物，因此科學家用它來研究并判斷水的污染情況。
小題3:　D
解析　推理判斷題。由文章最后一段可知，通過檢測藻類的光合作用可以確定水的質量，因此藻類的光合作用跟水的質量有密切關聯(lián)。
小題4:A
解析　主旨大意題。概括全文可知，本文主要講了科學家通過探聽水中植物的狀況來發(fā)現(xiàn)水污染的程度。文章第一段就點明了主旨。