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自然界中氧气的主要是____,消耗氧气的途径有:____(任写一点),工业上通常采用____的方法制取氧气,写出用过氧化氢制取氧气的化学方程式:____,举例说明自然界的水中溶解有氧气:____(任写一点).
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\u690d\u7269\u5149\u5408\u4f5c\u7528,\u52a8\u690d\u7269\u7684\u547c\u5438,\u5206\u79bb\u6db2\u6001\u7a7a\u6c14,2H2O2

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    Visas

    Travelers to France must have a valid passport (有效护照). Visitors from EEC (欧共体) countries and America do not need visas, but visitors from other countries should contact the nearest French consulate (领事馆) or tourist office about getting one before travelling.

    Arrival

    You could arrive at one of the two airports serving Paris.

    Charles de Gaulle is bigger and more modern. You can take a comfortable and inexpensive Air France bus to Porte Millot in the 16th district, then take a bus , the Metro or a taxi to your hotel. There are also city buses (No. 350 and 351) which go into Eastern Paris, Nation and the Gare de Train Station. A taxi takes about 40 to 50 minutes to reach the centre, and costs about 170 Francs. Add another 30 minutes for rush hours.

    Orly is the other major airport, which have mostly domestic (国内的) flights. Air France buses go to the Invalides Terminal, a convenient drop off place, where you can take the Metro or RER directly. A city bus (Orly bus) comes into the southern end of Paris at the Denfer-Rochereau Metro Station every 15 minutes. A taxi ride, not during rush hour, takes 30-40 minutes and costs about 120 Francs.

    If you arrive at a train station, you can follow the clearly posted signs towards the Metro or taxi stands.

    Money

    Many banks in Paris will change cash or travelers’ checks, and there are no special differences in rates (比率). Banking hours are 9 a.m. to 4:30 p.m. on weekdays. The exchanges window at the Gare du Nord is open until 10 p.m. on weekdays, and other station banks are open until 8 p.m.

    There are automatic (自动的) exchange machines at the Opera (the BNP Bank) and at No.66 on the Champs-Elysees that will change other bills into Francs. International VISA cards can be used in automatic tellers at many city banks.

    If you lose your credit card, here are some hotline numbers: American Express (Tel: 4777-7200); Diners Club (Tel: 4762-7575); Carte Bleu Visa (Tel: 4277-1190).