下列生活中常用物质属于纯净物的是（  ）

    Jack Ma's net worth increased $2.8bn overnight as Alibaba forecast sales growth that topped every analyst's estimate, despite the fact that China's economy is slowing down.

    Mr. Ma, aged 52 this year, is now the richest person in Asia and 14^th wealthiest in the world, according to the Bloomberg Billionaires Index. His net worth has climbed $8.5bn this year to $（4）8bn.

    The latest surge came after China's largest e-commerce company forecast 45 to 49 percent revenue(收入) growth in the year ending March, demonstrating how investments beyond online shopping are paying off. Shares in Alibaba, where Mr. Ma is chairman, rose 13 percent to a record high.

    Alibaba and Tencent, which dominate online shopping and social media, respectively have ventured(冒险) deeper into new areas from cloud computing services to streaming music and video as the country's economy slows. Alibaba is capturing more digital advertising spending by incorporating(合并) social elements such as video in its shopping sites.

    Alibaba is holding meetings with investors this week. On Friday, the former English teacher said he wasn't going to discuss corporate forecasts. He took the stage instead to describe how his company had become effectively the world's 22^nd largest economy—just after Argentina—in terms of transaction(交易) by never fearing to think big. Mr. Ma, who said Alibaba revises 10-year plans annually, foresaw the company becoming the fifth-largest eventually by 2036 by serving a burgeoning Chinese middle classes, taking advantage of global trade and making use of its valuable data.

    Ma's comments about the evolution of data-driven technology echoed Masayoshi Son, Chairman of Japan's SoftBank. SoftBank—Alibaba's largest shareholder—has invested billions in companies such as ARM with the intention of staking out a leading position in the future Internet of Things.

    “The Internet of Things is going to be big because in the past, machines drink electricity,” Mr. Ma told investors. “In the next 20 years, machines will drink data. In the future, no company, no country, no business can survive without data.”

— We eat _________.

阅读下面语段，回答下列各题。

智能家居安防

    ①智能家居安防系统是集信息技术、网络技术、传感技术、无线电技术、模糊控制技术等多种技术为一体的综合应用系统，是具有较强的技术性和前瞻性的新产品，

    ②通常，智能家居安防系统主要包括三大系统。

    ③第一是门禁系统。可靠安全的防盗门至关重要，它是家庭防护的第一道防线。门禁系统为主人提供坚固防范的同时，还提供了更多出入的方便。主人可以授权自己、家人、访客，通过密码、指纹、语音口令等智能识别方式方便地进出家门。

    ④第二是报警系统。报警系统由防盗报警系统、防火灾报警系统和防燃气泄漏报警系统等组成，它可以作为一种可靠且有效的方式让家庭能够避免外界侵入和自然因素引起的灾害。报警系统通过安装在室内外的各种传感器，将探测发出的信号最快地传递给相关人员。如烟雾火警探测器和可燃气泄漏探测器，它们在烟雾或可燃气达到一定的浓度时就会迅速发出警报以便用户知晓。

    ⑤第三是监控系统。监控系统是用于本地和远程了解特定区域情况，保留录像备查，起着威慑、监督、取证和管理作用的网络系统。监控系统具有实时监控功能，通过分布在室内的监视器、触摸屏等设备，可以监控住宅周边、门口、各个房间、室内通道等重点区域的实时情况。用户可通过手机随时随地查看家里的变化。系统还会自动将实时监控的影像通过硬盘录像功能录制下来，如果有盗贼闯入，就可以记录下盗贼的影像作为证据。

    ⑥此外，考虑到室内环境安全问题，环境监测系统也被划到安防这一块，顾名思义，环境监测系统主要是对室内环境进行监测的系统，包括甲醛探测仪、PM2.5探测器、二氧化碳探测器等。该系统的功能是实时对空气中某些有害物质的探测和对空气质量进行调节。

    ⑦智能家居安防系统是一个复杂的网络系统。各种智能防护设备通过信息通讯系统、网络系统彼此配合，协调工作，组成一个智能化的安防系统。它为我们享受高品质的智能居家生活提供了有力的保障。

（原文有改动）