①要在发挥主观能动性的基础上尊重客观规律

②要抓住时机实现事物的飞跃和发展

③要善于在矛盾的斗争性中把握矛盾的同一性

④要学会统筹考虑以实现最优目标

根据短文内容选择正确答案。

    Traveling is one of the most important things and people have been interested in it for many years. Modern traffic develops(发展) fast. So traveling to different places has become much easier than before.

    Staying healthy while traveling can make your trip happier. But do you know how to keep healthy during a trip? The following information may be useful for you.

    Before traveling:

    Wear comfortable shoes, a hat and sunglasses.

Take some necessary medicine with you. They can be used when you get sick or have other problems.

If you do lots of sports like walking or climbing during your trip, you should do some exercise for weeks or months before you leave.

    While traveling:

    Be sure not to eat dirty food or bad fruit.

    Have enough time to take a rest during your trip.

    Tap water is not safe, so drink bottled water and always clean the cover of the bottle.

回答下列问题：