Question

【题目】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(蛋白质)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(拟南芥). 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】

试题分析：植物的花每年春天开放，植物怎样知道什么时候开花呢？原来植物体内有一种叫FKF1的蛋白质，帮助植物知道时间的变化和季节的轮回。本文从生物学的角度给我们讲述了植物开花的秘密。

【1】A 推理判断题。题意：短文主要是有关什么的？ A. how plants “know” when to flower植物怎样知道何时开花；B. what people can do with plants人们用植物做什么；C. how seasons are changing季节是怎样变迁的；D. what kind of plant Arabidopsis is拟南芥是什么种类的植物。本文从生物学的角度给我们讲述了植物开花的秘密。故选A。

【2】D 细节理解题。题意：科学家做什么时发现了FKF1蛋白质？A. answering a question 答问题时；B. controlling the colours of flowers控制花的颜色时；C. planting flowers in the garden在花园里种花时； D. studying a plant called Arabidopsis研究一种叫Arabidopsi的植物时。由第三段的第一句“Researchers found the FKF1 protein when they were studying a plant called Arabidopsis”可知，本题选D。

【3】B 细节理解题。题意：植物开花的最好时间是什么？A. it rains in spring 春天下雨时；B. there is light in the late afternoon下午晚些时候有光线时；C. it is getting dark天快黑时；D. the sun goes down early太阳下山早时。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，本题选B。

【4】A 推理判断题。题意：科学家相信什么？ A. other plants also know when to flowers其它植物也知道何时开花；B. flowers are more valuable than fruits and vegetables花比蔬菜和水果有价值；C. people have known how to control when flowers come out人们知道怎样控制何时开花；D. if the weather is cold and days are short, plants will flower如果天冷，白天短，植物就会开花。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，正确选A。