Why do health experts suggest people should stand up for health?
A. Because standing burns more calories.
Because standing provides muscle activity people need.
C. Because standing helps keep blood sugar under control.
D. All of the above.
查看答案
What does the author want to tell us?
A. The harm of sitting too much.
B. How to keep healthy.
C. The relationship between sitting and standing.
D. Some habits are fatal.
X射线是德国物理学家（）发现的。
A. 库利吉
B. 居里夫人
C. 伦琴
D. 万莱沃纳
传统的X射线技术用的是透视原理。
A. 对
B. 错
人员进入洁净区的程序是（）。
A. 换鞋→换外衣→穿洁净服→洗手→消毒→进入净化区
B. 换鞋→换外衣→洗手穿洁净服→消毒→进入净化区
C. 换鞋→换外衣→消毒→洗手→穿洁净服→进入净化区
D. 换鞋→洗手→换外衣→穿洁净服→消毒→进入净化区
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