题干

人站在平面镜前,当他向平面镜走近时,发生的现象是(   )


A:像不变,像到镜面的距离变小

B:像不变,像到镜面的距离不变

C:像变大,像到镜面的距离变大

D:像变大,像到镜面的距离变小

上一题 下一题 0.0难度 选择题 更新时间:2019-03-18 10:08:37

答案(点此获取答案解析)

A

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阅读理解

    Internet Security Awareness

    MS-ISAC

    “Kids Safe Online”

    2017 Virginia Poster Contest(比赛)

    Official Rules

    Contestants

    The contest is open to all Virginia public, private Kindergarteners -12 in the United States, District of Columbia and the U.S. Territories (领土).

    Judging Criteria

    Posters will be judged on the following criteria:

    Clear message conveyed by the text and artwork

    Creativity, originality and artistic quality

    Visual clarity - easily read

    Bright and colorful

    Must not use published materials.

    Winners

    Virginia will select the top 5 winning posters from each grade group (K-5, 6-8, 9-12) and send them to the National Multi-State Information Sharing and Analysis Center (MS-ISAC) Internet Security Awareness Poster Contest. The Virginia winners will receive a certificate of appreciation. MS- ISAC will select four winners in each grade and award a prize. These winners will have the honor of having their artwork made into a poster calendar which will be handed out throughout the country and may also be used in campaigns to raise awareness among children of all ages about the Internet.

    Posters will not be returned!

    Deadline

    All posters must be received by midnight, Jan. 6, 2017.

    Poster should be mailed to:

    Kids Safe Online Poster Contest Virginia Information Technology Agency Commonwealth Security & Risk Management

    11751 Meadowville Lane Chester, VA 23836

    Electronic posters can be sent to: CommonwealthSecurity@virginia.gov

    Contest Timeline

    Now through Jan. 6, 2017

    Students create their posters and the school can choose up to 15 posters to send to VITA by midnight January 6, 2017.

    No Later than Jan. 27, 2017

    Virginia posters will be judged and the top 15 posters will be sent to MS-ISAC for national judging.

    Jan. 30 to March 3, 2017,

    MS-ISAC will perform national judging. Winners will be declared no later than March 24, 2017