人长时间处在缺氧环境中会出现窒息症状．在呼吸过程中，吸进的氧气进入人体后最终到达的部位是（   ）

    Sometimes we can get so caught up in the stress and worry of our personal lives that our minds become too confused to operate effectively.This is especially dangerous in a test-taking situation.After hours of reading and studying,our brains can lock up in a state of overload.

    In a stressful situation it's often a must to clear your mind completely to allow your brain to refresh itself and recalibrate all of its functions.But when you're tense,clearing your mind isn't so easy!Try this relaxation technique if you think your brain has seized up from information overload.

    ⒈Set aside at least five minutes for quiet "clearing" time.If you're at school,see if you can put your head down somewhere or find an empty room or quiet space.If necessary,set a watch (or phone) alarm or ask a friend to tap you on the shoulder at a designated time.

    ⒉Think of a time or place that puts you into a complete state of peace.This place will vary from person to person.Have you ever sat on the beach watching the waves come in and realized you've "zoned out" fora while?This is the sort of experience you're looking for.Other experiences that make us zone out could be: Sitting in the dark and staring at Christmas tree lights—remember how peaceful that feels?

    ⒊Cover your eyes and go to your "place".If you are at school preparing for a test before class,you may simply rest your elbows on the desk and put your hands over your eyes.For some people,it may not be a good idea to put your head down.(You might fall asleep!)

    Don't let any thoughts creep into your head.As soon as you start to think about a test problem,clear away the thought and concentrate on your peaceful place.

    ⒋Snap out of it!Remember,this is not nap time.The point here is to refresh your brain.After five or ten minutes of clearing time,take a brisk walk or take a drink of water to re-energize your mind and body.Stay relaxed and resist the urge to think about the things that are stressing you out or clogging your brain.Don't let your brain go back to freeze-out.

    Now go on with your test or study session refreshed and ready!

中和反应的实质是酸中的 ____和碱中 ____的反应生成  ____。

   This is No. 12 High School. My friend Dongdong is in this school. Dongdong has short hair, a big nose, a small mouth and big eyes. He is thirteen. He is in Class Two, Grade Seven. He's a good student. He has two good friends in his school. They are Jim and Jack. They're brothers（兄弟）. They are fourteen. They have small noses, small eyes, but they’re very tall（高的）. Jim, Jack and Dongdong are in the same class. Mr. Lee is their（他们的）teacher. They are good friends.