Question

【題目】It happens every spring. Flowers come out everywhere on the same day. But how do plants “know” when to flower?

For years, it has been a difficult question for scientists. But a US research group may have finally answered it—the secret lies in a protein(蛋白質(zhì))called FKF1. This helps plants to know when the days become long and when they get short. Then they can tell the seasons are changing.

Researchers found the FKF1 protein when they were studying a plant called Arabidopsis(擬南芥). It is sensitive(敏感的)to sunlight, and can be made active by sunlight.

Plants produce this protein every day in the late afternoon all year. If there is no light at this time, for example in winter when the sun goes down early, the protein won’t be active. But when spring comes and the days get longer, the FKF1 protein can be made active by day light and the plants “know” it is time to flower. “If there is light in the late afternoon, plants will know that the days are getting longer and that it is the best time for flowers to come out,” explained Takato Imaizumi, leader of study. But when conditions are poor for growing, such as during autumn or winter when the weather is cold and days are short, plants won’t flower.

Although researchers have only studied how the FKF1 protein works in the Arabidopsis, they believe that it is the same with many other plants, including crops such as rice and wheat. This could be useful to the agricultural industry.

“If we can control when flowers come out, we might be able to increase crop production,” Imaizumi said.

【1】 The passage is mainly about ____.

A. how plants “know” when to flower

B. what people can do with plants

C. how seasons are changing

D. what kind of plant Arabidopsis is

【2】Scientists found the FKF1 protein when they were____.

A. answering a question

B. controlling the clours of flowers

C. planting flowers in the garden

D. studying a plant called Arabidopsis

【3】The best time for flowers to come out is when____.

A. it rains in spring

B. there is light in the late afternoon

C. it is getting dark

D. the sun goes down early

【4】Scientists believe that____.

A. other plants also know when to flowers

B. flowers are more valuable than fruits and vegetables

C. people have known how to control when flowers come out

D. if the weather is cold and days are short, plants will flower

Answer 1

【答案】

【1】A

【2】D

【3】B

【4】A

【解析】

試題分析：植物的花每年春天開放，植物怎樣知道什么時候開花呢？原來植物體內(nèi)有一種叫FKF1的蛋白質(zhì)，幫助植物知道時間的變化和季節(jié)的輪回。本文從生物學(xué)的角度給我們講述了植物開花的秘密。

【1】A 推理判斷題。題意：短文主要是有關(guān)什么的？ A. how plants “know” when to flower植物怎樣知道何時開花；B. what people can do with plants人們用植物做什么；C. how seasons are changing季節(jié)是怎樣變遷的；D. what kind of plant Arabidopsis is擬南芥是什么種類的植物。本文從生物學(xué)的角度給我們講述了植物開花的秘密。故選A。

【2】D 細節(jié)理解題。題意：科學(xué)家做什么時發(fā)現(xiàn)了FKF1蛋白質(zhì)？A. answering a question 答問題時；B. controlling the colours of flowers控制花的顏色時；C. planting flowers in the garden在花園里種花時； D. studying a plant called Arabidopsis研究一種叫Arabidopsi的植物時。由第三段的第一句“Researchers found the FKF1 protein when they were studying a plant called Arabidopsis”可知，本題選D。

【3】B 細節(jié)理解題。題意：植物開花的最好時間是什么？A. it rains in spring 春天下雨時；B. there is light in the late afternoon下午晚些時候有光線時；C. it is getting dark天快黑時；D. the sun goes down early太陽下山早時。由第三段里的“If there is light in the late afternoon, plants will know that the days are getting longer and that it is the best time for flowers to come out,” 可知，本題選B。

【4】A 推理判斷題。題意：科學(xué)家相信什么？ A. other plants also know when to flowers其它植物也知道何時開花；B. flowers are more valuable than fruits and vegetables花比蔬菜和水果有價值；C. people have known how to control when flowers come out人們知道怎樣控制何時開花；D. if the weather is cold and days are short, plants will flower如果天冷，白天短，植物就會開花。由第四段的第一句“Although researchers have only studied how the FKF1 protein works in the Arabidopsis, they believe that it is the same with many other plants”可知，正確選A。