在这个反应中，还原剂是____；发生还原反应的物质是____．

A．C；  B．H₂；C．CO；  D．H₂O．

图示为研究二力平衡条件的实验装置，下列关于这个实验的叙述错误的是（　　）

    The cultures of the East and the West really distinguish from each other a lot. This is because the culture systems are two 1 systems on the whole.

    The origin of the eastern culture is mainly from two countries: China and India. Both of the two cultures are gestated（孕育） by 2. In China, the mother river is the Yellow River, 3 the Indian one is the Hindu River. These two cultures have 4 for several thousand years and formed their own styles. Then in Tang Dynasty of China, the Chinese culture 5 went overseas to Japan, 6 into the Japanese society and 7 the Japanese culture nowadays. Though a bit different from the Chinese one, it 8 to the same cultural system.

    When the two mother rivers gave birth to the eastern culture, another famous culture was 9 on the Mesopotamian Plain(米索不达米亚平原): the Mesopotamian Civilization. This civilization later on developed into the cultures of the Ancient Greece and Ancient Rome. And these two are well-known as the 10 of the European culture. 11 the Chinese culture, the European one is also 12 to waters. When the colonists(殖民者) of England 13 in America, their culture went with them over the Atlantic Ocean. So the American culture doesn't 14 from the European one a lot.

    At the same time, the 15 of the language systems adds to the cultural differences. In the East, most languages belong to the pictographic(象形文字的) languages while the Western languages are 16 based on the Latin system, for example, the one I'm using to write this paper.

    Other factors like human race difference counts 17 . However, 18 the far distance and the steep areas between the East and West, the two cultures seldom 19 until recent centuries. 20 they grew up totally in their own ways with almost no interference from the other.

阅读短文，回答问题。

手表的启示

    有一天，我从学校里跑出来，流着泪，很伤心地走回家。

    妈妈抱着弟弟，站在门口。弟弟向我招手，妈妈亲切地微笑着，欢迎我回来。

    但是，我那带着眼泪的脸，使妈妈很惊奇。她连忙拉着我的手，一边走进去，一边问我说：“为什么这般伤心？”

    我一边抹着（zhe  zhāo）眼泪，一边呜呜咽（yè  yàn）咽地说：“妈妈，我想要做的事，老师总不让我做。”“呀！到底是什么事？”妈妈温和地问我。

    “学校要开家长会……要演节目……但是老师不让我当主角（jiǎo  jué），却只要我在后台工……工作！那小龙平时又很不爱文艺，这次反做了主角！”我呜呜咽咽地，连话也说不清楚。

    妈妈伸出手来，要我看看她戴着的手表。

    “云，你看，这手表上面有些什么东西？”妈妈一面擦干我的眼泪，一面温和地问。

    “那是一块玻璃，两根指针。”我回答说。

    妈妈把弟弟放在一旁，脱下手表，把表壳（ké  qiào）打开，又问我说：“你看，里面是些什么？”

    “是小齿轮和螺丝！”这时我完全忘记了我的伤心事。

    妈妈继续说：“当表的针不走，或走得不准的时候，别人就会说‘这表是虚有外表’。可是怎样才能使它会走，并且走得准确呢？就得靠这些小齿轮和螺丝，也就是这些别人看不到的部分。”

    停了一会儿，妈妈又望着我意味深长地说：“这是不被人注意的工作，但却是最重要的，而且是不能够没有的工作。”