问题 选择题

下列叙述正确的是

A.图I装置中通入N2和O2的作用是相同的

B.图Ⅱ中甲、乙两装置产生喷泉的原理一样

C.图Ⅲ①装置中镁片是原电池的负极;②装置中镁片是原电池的正极

D.图Ⅳ分液漏斗盛硝酸能证明非金属性N>C>Si,盛硫酸能证明非金属性S>C>Si

答案

答案:C

题目分析:A、O2发生还原反应,而N2不参加负极反应,错误;B、氨气溶于水,H2O2分解产生大量O2,错误;C、Mg比Al易与稀硫酸反应,则①中Mg是负极,Al才能与NaOH溶液反应,则②中Al是负极,正确;D、硝酸具有挥发性,因此不能证明非金属性N>C>Si,错误。

单项选择题
单项选择题

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 made Professor Broad continue his search for more information on McKay()

A.A uniform of McKay.

B.A footnote about McKay.

C.A book on McKay.

D.A picture of McKay.