不分散聚合物加重钻井液中，聚合物的作用主要是絮凝和包被钻屑、增效膨润土和（）重晶石。
题型：单项选择题
问题：
不分散聚合物加重钻井液中，聚合物的作用主要是絮凝和包被钻屑、增效膨润土和（）重晶石。
A、包被
B、清除
C、絮凝
D、沉淀
题型：单项选择题
Yoga（瑜伽）is an ancient practice that helps create a sense of union in body, mind, and spirit. It brings us balance. After a long time of practice yoga, you no longer just practice it — you love it.
Yoga becomes part of your physical life. Your body grows stronger, more toned（有弹性的）, and more flexible as you move from one pose to another. I spent a week in Mexico at a yoga retreat, and it was the first vacation on which I lost weight. “Rather than building muscles, yoga builds muscle tone,” says Shakta Kaur Khalsa, author of KISS Guide to Yoga. “Because yoga helps maintain a balanced metabolism（新陈代谢）, and it also helps to control weight. Additionally, yoga stretches muscles lengthwise, causing fat around the cells disappear, thus losing weight
.”
I do yoga poses throughout the day. After hours at my computer, I stretch my stiff shoulders and arms. When I need an increase in energy, I do energizing poses. When I am feeling exhausted at the end of the day, I do restorative（恢复体力的）poses.
Yoga becomes part of your mental life. Yoga teaches you to focus on breathing while you hold the poses. This attention to breath is calming; it dissolves（使消除）stress and anxiety. I use yogic breathing on the tennis court, in the dentist’s chair, and when I’m stuck in traffic.
You should always leave a yoga practice feeling energized, but not tired. If you feel tired after yoga, it means you spent the time “fighting” yourself, trying to force yourself into poses. In yoga, you “surrender” to the poses by letting go of the tension.
64. What will be talked about if this passage continues?
A. Yoga is becoming part of your spiritual life.
B. Yoga is becoming popular all over the world.
C. The disadvantages of yoga.
D. Encouraging people to do yoga.
65. According to the second paragraph, yoga can help people ___.
A. grow tall B. lose weight C. be flexible in thinking D. make friends
66. Why does a person feel tired after yoga?
A. Because when practicing yoga, people will consume a lot of energy.
B. Because he or she surrenders to the poses by letting go of the tension.
C. Because yoga doesn’t benefit all the people.
D. Because he or she doesn’t do yoga poses naturally.
67. What would be the best title for this passage?
A. What’s yoga? B. How do I do yoga poses?
C. The benefits of yoga. C. The varieties of yoga.