The Internet affords anonymity to its users, a blessing to privacy and freedom of speech. But that very anonymity is also behind the explosion of cyber-crime that has (1)_____ across the Web.

    Can privacy be preserved (2)_____ bringing safety and security to a world that seems increasingly (3)_____?

    Last month, Howard Schmidt, the nation’s cyber-czar, offered the federal government a (4)_____ to make the Web a safer place—a “voluntary trusted identity” system that would be the high-tech (5)_____ of a physical key, a fingerprint and a photo ID card, all rolled (6)_____ one. The system might use a smart identity card, or a digital credential (7)_____ to a specific computer, and would authenticate users at a range of online services.

    The idea is to (8)_____ a federation of private online identity systems. Users could (9)_____ which system to join, and only registered users whose identities have been authenticated could navigate those systems. The approach contrasts with one that would require an Internet driver’s license (10)_____ by the government.

    Google and Microsoft are among companies that already have these “single sign-on” systems that make it possible for users to (11)_____ just once but use many different services.

    (12)_____ , the approach would create a “walled garden” in cyberspace, with safe “neighborhoods” and bright “streetlights” to establish a sense of a (13)_____ community.

    Mr. Schmidt described it as a “voluntary ecosystem” in which “individuals and organizations can complete online transactions with (14)_____, trusting the identities of each other and the identities of the infrastructure (15)_____ which the transaction runs”.

    Still, the administration’s plan has (16)_____ privacy rights activists. Some applaud the approach; others are concerned. It seems clear that such a scheme is an initiative push toward what would (17)_____ be a compulsory Internet “driver’s license” mentality.

    The plan has also been greeted with (18)_____ by some computer security experts, who worry that the “voluntary ecosystem” envisioned by Mr. Schmidt would still leave much of the Internet (19)_____. They argue that all Internet users should be (20)_____ to register and identify themselves, in the same way that drivers must be licensed to drive on public roads.

答案精析：all指代前文所说实体钥匙、指纹和带照片的身份证，此处使用独立主格结构，表示该系统相当于实体钥匙、指纹和带照片的身份证三者合一，roll into表示“使合为一体”，故B选项为正确答案。

错项排除：A选项带入原文表示“三者被一种东西卷入”，语义不通，故错误。roll不与from和over搭配，故C、D选项错误。

长难句分析：Last month, Howard Schmidt, the nation’s cyber-czar, offered the federal government a proposal to make the Web a safer place—a “voluntary trusted identity” system that would be the high-tech equivalent of a physical key, a fingerprint and a photo ID card, all rolled into one.

本句主干为Howard Schmidt offered the federal government a proposal，是主语+谓语+双宾语的结构。the nation’s cyber-czar是Howard Schmidt的同位语，不定式to make the Web a safer place是后置定语，修饰proposal。a “voluntary trusted identity” system是proposal的同位语，其后的that引导的从句是system的定语从句，为主系表结构，其中of a physical key, a fingerprint and a photo ID card是介词短句作后置定语，修饰equivalent，all rolled into one是独立主格结构。

句意为：上个月，国家网络安全总督霍华德·施密特向联邦政府提出一项提高网络安全性的提议：一个相当于实体钥匙、指纹和带照片的身份证三者合一的高科技“身份自动识别”系统。