“文化大革命”期间，我国民主法制遭到严重践踏最为典型的事件是（  ）

标准氢氧化钠溶液中和醋酸时，当溶液的pH等于7，则此时(　　)

    Now is the best time for Hong Kong shopping lovers, as most shops and markets are having their seasonal sales. With the same amount of money, you can find different kinds of goods in this city. Women, young and old, rarely resist the attraction of this shopping paradise(乐园) at this time of year. Lovers will surely have an exciting Christmas and New year's Eve celebrations at the Time Square or in the western styled bars. Spending your holiday in Hong Kong will be easy too, as several packing tours are available from CZL Travel Service, with four-day tours for less than 15,000 yuan.

    Tour package 1(3,200 yuan): a 4-day-tour including three nights' accommodation(住宿), science helicopter flight, night ferry tour of Victoria Harbor and shuttle bus to the park to view the city at night.

    Tour package 2(1,880yuan): a 4-day-shopping tour including three nights' accommodation, tour to Golden Beach and the Vex work Museum, shuttle bus to the Peak and shopping opportunities.

    Tour package 3 (1,480 yuan): a 4-day-DIY-tour including three nights' accommodation in a four-star hotel and total freedom to do what you want, when you went.