题干

氢气是一种具有广泛用途的物质,下列关于氢气的叙述不正确的是(   )

A:用氢气充灌探空气球是因为相同条件下,氢气的密度最小

B:氢气具有可燃性,可以做燃料

C:点燃氢气与氧气的混合气体时,一定会发生爆炸

D:氢气在发生化学变化时的最小微粒是氢原子

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答案(点此获取答案解析)

C

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    International travelers, whether traveling for business or pleasure, will find themselves solo from time to time. Here are a few ways to meet new people and perhaps even get new travel chances.

    Make yourself friendly

    Be relaxed and polite. Remember to put yourself in social activities. Restaurants, shops and parks are all great places to meet people. If you want to make local friends in a country, stay near the place the locals often visit.

    Show your photo album(影集)

    Keep a small photo album in your bag when you travel. Photos of family, friends and pets will help your new friends learn more about you and give you things to talk about. They will share their own stories with you, and it will help you learn more about your new friends.

    Share something special

    Can you help your new friends improve their Chinese? Can you cook a traditional Chinese meal? By sharing your skills, you can have a close friendship with your new friends that they won't soon forget.

    Give some gifts

    Many foreigners love Chinese goods but have to pay a lot when buying them in their homeland, so you'd better prepare some gifts such as silks, tea and works of art. They are always popular.

    Exchange flats

    If you and your new friends get along well, you can give them your information and plan to exchange flats for your next trip. Then you can visit their countries and stay in their houses while they stay in yours. In this way you will improve your friendship and live like a local abroad, but pay less for traveling.