What does the second paragraph tell us？

A．Environmental pollution may have far-reaching consequences.

B．Any or all of these ecosystem functions may be impaired or destroyed by pollution.

C．Ecosystems perform. many important services for the earth's environment.

D．Pollution also has a great influence on natural resources.

A．Ant cemeteries exhibit elements of activation but not inhibition, a proposition formerly questioned by Turing's theory.

B．Ant cemeteries exhibit Turing patterns in the absence of the predator-prey system.

C．Ant cemeteries involve self-amplification activation, as opposed to amplification from outside sources.

D．Ants are considered a higher organism, in which Turing patterns have never previously been established.

E．Turing's theory has only explained the distribution of ants across the ecosystem, until now.

Who giggles after Komiyama comes into the room according to the passage？

A．The old woman Komiyama herself.

B．Komiyama"s fantastic pet robot.

C．A mechanical companion in Star Wars.

D．A naughty Japan"s creation Astro Boy.

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. User 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 "drive'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.

【B1】

A．swept

B．skipped

C．walked

D．ridden

若S和T均為正常算子，滿足ST^*=T^*S和TS^*=S^*T，證明：S+T與ST也是正常算子。

設S和T是Hilbert空間H中使得ST在H中稠定的線性算子．證明(ST)^*T^*S^*；若D(S)=H且S是有界的，證明(ST)^*=T^*S^*．

設有下列文法： PROGRAM→begin d；S end S→d；S｜sT T→εf；sT (1)試構造該文法的LL(1)分析表。 (2)給出句子begin d；s；s end的分析過程。

證明：

(1) (αS+βT)^*=αS^*+βT^*，當α，β∈K；

(2)(ST)^*=T^*S^*；

(3)(T^*)^-1=(T^-1)^*

This passage is mainly about Hemingway's ______ .

A．life

B．background

C．novels and writing style

D．ideas