正确答案: A

电解水生成氢气和氧气，说明水是由氢气和氧气组成的

题目：下列说法中错误的是（ ）

解析：A

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举一反三的答案和解析：

[单选题]AWhen you look at the sky at night，the moon looks bigger than the stars． In fact，the moon is much smaller than the stars．It is much smaller than the earth． But the moon is much closer to us than any star． That is why it looks so big． If you hold a coin close．to your eye，it looks big．If you look at it across the room，it looks small．The moon moves around the earth． It makes one trip in about four weeks． The moon looks flat(扁的)to us． But it is a round ball，like the earth．People once thought the moon had fire(火) on it． They thought the fire made it bright．Now we know the moon is like a mirror( 镜子 )． It gets its light from the sun Our sunlight comes from the sun，too: What is the sun? The sun is star． The stars we can see have their own light． There are many big stars we can-t see． Their light has burned out． Others are still bright，but they are so far away that we can-t see them． The sun looks bigger and much brighter than other stars because it is the nearest of all stars． The sun and the other stars we see are very hot，but the air around us saves us from(使------免于) the heat(热量) of the sun．The sun gives us light and warmth．It makes plants grow and leaves turn green． It makes life possible on our earth．It is a life-giving star．

it is the closest to the earth

解析：．21.C 【解析】由第一段中。But the moon is much closer to us than any star.打可知。

[单选题]40: He has several books on the desk，but _________ of them is on history．

none

解析：40.A【解析】句意。他桌子上有好几本书，但没有一本是有关历史的．none和all修饰三者或三者以上，neither和both修饰两者。由题意可知表示否定，且是三者或三者以上，用none．

[单选题]27． When Johnny's parents saw the report， they were happy because ________．

they thought Johnny was not poor in English longer

解析：27．D【解析】Johnny将成绩从F改为了A，所以他父母以为他的英语提高了，故选D。

[单选题]12．

places

解析：D【解析】where引导的从句修饰名词places“地方”，其他名词概括不全面。

[单选题]10． Who can __________ the question?

answer

解析：10.c【解析】answer the question意为“回答这个问题”。

[单选题]一、选择题（

每小题4分，共40 1．下列是一元一次不等式的是（ ）

[单选题]44．—Did you call Sara back?—I didn’t need to，_________we’ll have a meeting together tonight．

because

解析：44．C【解析】句意：——你给萨拉回电话了吗？一不必了，因为我们今晚要在一起开会．因为后面的句子是解释不打电话的理由，表示原因。故选C 项。