下图漫画形象地描述了一直困扰公安部门的一种车牌使用现象。某人设计发明了汽车翻牌器以逃避电子眼抓拍和交警的管理，从而不受违章处罚。这项发明设计，违背了技术设计中的（   ）

阅读下面短文，从各题所给的A、B、C、D四个选项中选出最佳选项。
B
Join Us for a Day at Sun Valley Amus ement Park

    Children aged 10 to 14 are invited to take part in the "Event of the Summer" at
Sun Valley Amusement Park, the most popular amusement park on the East Coast.
Sun Valley has more than 80 amusement rides. For sports lovers, there are
basketball courts, an indoor baseball field and climbing walls.
    No amusement park would be complete without a gift shop. Sun Valley
has two.
    You won't want to miss out on this day of fun. Join us at Sun Valley Amusement Park on July 14. Register (登记) early.
    • The cost of the trip is $ 25. This includes tickets and all rides.
    • We suggest that all children bring lunch.
    • Buses leave at 9.00 AM and return at 5.00 PM.
    • Rain Date: Wednesday, July 16.
    Register at the Children's Recreation Center at the Town Hall by July 3.
    A one-day registration will also be held on July 1 at the Brown School.
    For more information, call Jane Parks at 555-7267.

铁钉、钢针与磁石接触或摩擦后，有时会具有____，用同样的磁石摩擦，钢针比铁钉具有的磁性强。

若一个DNA分子中的鸟嘌呤占整个DNA分子碱基的27％，并测得DNA分子一条链上的腺嘌呤占这条链碱基的18％，则另一条链上的腺嘌呤所占的比例是

北宋东京（今开封）“通宵不绝”的夜市和“终日居此，不觉抵暮”的瓦子（文娱场所）里，随处可见流连忘返的市民身影。这一生活图景表明