不同浓度的生长素影响某植物乙烯生成和成熟叶片脱落的实验结果如图所示。下列有关叙述正确

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问题:

不同浓度的生长素影响某植物乙烯生成和成熟叶片脱落的实验结果如图所示。下列有关叙述正确的是()

A.乙烯浓度越高脱落率越高

B.脱落率随生长素和乙烯浓度增加而不断提高

C.生长素和乙烯对叶片脱落的作用是相互对抗的

D.生产上可喷施较高浓度生长素类似物降低脱落率

考点:高中生物植物激素调节植物激素调节题库
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已知小磁针静止时的位置如图,判断磁铁的N、S极,通电螺线管的电流方向及电源的正负极.

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炮采工作面是用爆破方法破煤。

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根据《国家金库条例实施细则》,分成收入的计算,按照财政管理体制划分的预算级次逐级办理。

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Eddie McKay, a once forgotten pilot, is a subject of great interest to a group of history students in Canada.
It all started when Graham Broad, a professor at the University of Western Ontario, found McKay’s name in a footnote in a book about university history. Mckay, was included in a list of university alumni who had served during the First World War, but his name was unfamiliar to Broad, a specialist in military history. Out of curiosity, Broad spent hours at the local archives in a fruitless search for information on McKay. Tired and discouraged, he finally gave up. On his way out, Broad’s glance happened to fall on an exhibiting case showing some old newspapers. His eye was drawn to an old picture of a young man in a rugby uniform. As he read the words beside the picture, he experienced a thrilling realization. "After looking for him all day, there he was, staring up at me out of the exhibiting case," said Broad. Excited by the find, Broad asked his students to continue his search. They combed old newspapers and other materials for clues. Gradually, a picture came into view.
Captain Alfred Edwin McKay joined the British Royal Flying Corps in 1916. He downed ten enemy planes, outlived his entire squadron as a WW1 flyer, spent some time as a flying instructor in England, then returned to the front, where he was eventually shot down over Belgium and killed in December 1917. But there’s more to his story. "For a brief time in 1916 he was probably the most famous pilot in the world," says Broad. "He was credited with downing Oswald Boelcke, the most famous German pilot at the time." Yet, in a letter home, McKay refused to take credit, saying that Boelcke had actually crashed into another German plane.
McKay’s war records were destroyed during World War Two air bombing on London-an explanation for why he was all but forgotten.
But now, thanks to the efforts of Broad and his students, a marker in McKay’s memory was placed on the university grounds in November 2007. "I found my eyes filling with tears as I read the word ’deceased’ next to his name," said Corey Everrett, a student who found a picture of Mckay in his uniform. "This was such a simple example of the fact that he had been a student just like us, but instead of finishing his time at Western, he chose to fight and die for his country.\

What did the students find out about McKay

A. He trained pilots for some time.
B. He lived longer than other pilots.
C. He died in World War Two.
D. He was downed by the pilot Boelcke.

题型:单项选择题

净度检验中,可进行全试样分析,也可进行两份半试样分析,这里两份半试样就是2.5试样的意思。

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