题干

硫燃烧产生的二氧化硫气体会造成空气污染。为避免二氧化硫污染空气,某教师对教材中“硫在空气和氧气中燃烧”的实验进行了改进与创新,设计了如图甲所示的实验装置:

【实验原理】

① B装置是燃烧匙固定在带有A导管的单塞上,硬质玻璃管透光性好,不影响实验现象的观察;

② C装置的广口瓶中盛放氢氧化钠溶液可吸收二氧化硫气体,避免污染;

③ 打开D装置中的阀门,气体就会从左向右依次进入装置。

【实验过程】

步骤一:将硫粉放在燃烧匙上,在空气中点燃后,迅速伸入硬质玻璃管内(如图B装置),打开阀门,观察硫在空气中燃烧的现象;

 步骤二:将导管a伸入盛有氧气的集气瓶中(如图A装置),观察硫在氧气中燃烧的现象。

 【交流讨论】

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    Why do many people play sports? You might say “to get exercise'' and you'd be right. To have fun? That's true, too. But there's more.____According to the Women's Sports Foundation, girls who play sports get a lot more than just fit.

    Girls who play sports do better in school. ____But research shows that girls who play sports do better in school than those who don't. Exercise improves learning, memory, and concentration, which can give active girls an advantage in the classroom.

    Girls who play sports learn teamwork and goal-setting skills. Sports teaches valuable life skills. When you working with coaches, trainers, and teammates to win games and achieve goals, you're learning how to be successful. ____

    Sports are good for a girl's health. In addition to being fit and maintaining a healthy weight, girls who play sports are also less likely to smoke. And later in life, girls who exercise are less likely to get breast cancer.

    ____ Girls who play sports feel better about themselves. Why? It builds confidence when you know you can practice, improve, and achieve your goals. Sports are also a feel-good activity because they help girls get in shape, maintain a healthy weight, and make new friends.

    Exercise cuts the pressure. Playing sports can lessen stress and help you feel a little happier. How? ____ Friends are another mood-lifter. And being on a team creates tight bonds between friends. It's good to know your teammates will support you—both on and off the field!

A. Please take action to play games.

B. Playing sports boosts self-confidence.

C. Playing sports is good for your grades.

D. In fact, there are at least 5 more reasons.

E. Those skills will serve you well at work and in family life.

F. You might think that athletics will take up all your study time.

G. The brain chemicals released during exercise improve a person's mood.