The price of a bitcoin topped $900 last week, an enormous surge in value that arrived amidst Congressional hearings where top U.S. financial regulators took a surprisingly optimistic view of digital currency. Just 10 months ago, a bitcoin only sold for $13. The【C1】______increase was big news across the【C2】______, from Washington to Tokyo to China, and it left many asking themselves: "What on earth is a bitcoin?" It's a good question. Bitcoin is a digital currency, meaning it's money controlled and stored entirely by computers【C3】______across the internet, and this money is finding its way to more and more people and businesses around the world.【C4】______it's much more than that, and many people—【C5】______the sharpest of internet【C6】______as well as seasoned economists—are still【C7】______to come to terms【C8】______its many identities. Bitcoin isn't just a currency, like dollars or euros or yen. It's a way of making【C9】______, like PayPal or the Visa credit card network. It lets you hold money, but it also lets you spend it and【C10】______it and move it from place to place, almost as cheaply and easily as you'd send an email. As the press so often points out, bitcoin lets you do all this without【C11】______your identity. But at the same time, it's a system that operates【C12】______in the public view. All bitcoin【C13】______are recorded online for anyone to see, lending a certain transparency to the system, a transparency that can drive a new【C14】______in the economy. Bitcoin is much more than a money service. It's a re-imagining of【C15】______finance, something that【C16】______barriers between countries and frees currency from the control of federal governments. Bitcoin is controlled by open source software that operates according to the【C17】______of mathematics—and by the people who collectively supervise this software. The software【C18】______on thousands of machines around the world, but it can be changed It's just that a majority of those supervising the software must【C19】______to the change.【C20】______, bitcoin is kind of like the internet, but for money.
单选题
【C1】
【正确答案】
A
【答案解析】解析：第一段提到10个月以前比特币的售价仅为13美元，而上周比特币的价格飙涨到900美元，且an enormous surge in value也表明了比特币价格飞涨。此处应填入A项，sharp increase表示”飞涨”，符合语义逻辑。
单选题
【C2】
【正确答案】
D
【答案解析】解析：由空格前的across可知此处是消息传播的范围，空格后的from Washington to Tokyoto China为具体描述。D项globe表示“全球”，符合语义。
单选题
【C3】
【正确答案】
A
【答案解析】解析：该空格需填入动词过去分词与表示范围的across the internet构成后置定语修饰computers。互联网上电脑遍布，故A项spread为答案，表示“散布(世界各地的)因特网上的电脑”。
单选题
【C4】
【正确答案】
C
【答案解析】解析：上一句提到“这种货币在全球人们和商户中找到了市场”，接着在空格后表明“它的发展程度远非如此”(much more than that)。可见空格处应是表转折关系的逻辑词，答案只能选C项but“但是”。
【答案解析】解析：从下一句中的But at the same time及operates…in the public view判断，这两句话是转折关系。revealing your identity表示“泄漏身份”，即“比特币的交易完全是匿名的，不会泄露身份”，与下句的in the public view能形成语义转折，选B项。
单选题
【C12】
【正确答案】
C
【答案解析】解析：下文提到比特币…are recorded online for anyone to see且transparency to the system．与空格后的in the pubic view相呼应。由此可判断这里需要填入一个副词来修饰其公开透明的程度。C项completely“完全地”，符合语义逻辑。
单选题
【C13】
【正确答案】
D
【答案解析】解析：前一句中的Bitcoin lets you do all this指代上一段提及的把比特币当作其他货币来储蓄、花费。本句最后一个单词为economy，因此所填入词应该属于经济活动范畴内，故选D项transactions“交易”。
【答案解析】解析：本句提到比特币由开源软件(open source software)控制，而该软件的运营是根据数学(mathematics)的——。选项都有“法同，法规”的意思。A项law是普通用词，泛指由最高当局所制订、立法机构所通过的任何成文或不成文的法规或条例，还可以表示“规律、定律”，在这里laws of mathematics表示“数学定律”。