测量值与真实值之差在测量值中所占的比例为( )。 A.绝对误差 B.相对误差 C.

题型:单项选择题

问题:

测量值与真实值之差在测量值中所占的比例为( )。

A.绝对误差
B.相对误差
C.系统误差
D.偶然误差

考点:西药执业药师药学专业知识(一)西药执业药师药学专业知识(一)
题型:单项选择题

架空避雷线和避雷网宜采用截面不小于( )mm2的镀锌钢绞线。

A.20
B.25
C.30
D.35

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Intense physical exercise is not the only way to better health. Studies show that walking several times a week can lower risk of many diseases. They include heart disease, stroke, diabetes, bone loss, arthritis (关节炎), and depression. Walking also can help you lose weight.
Fast walking is good for the heart. It lowers the blood pressure. It raises the amount of good cholesterol(胆固醇)in the blood. Researchers say walking can sharply reduce the risk of suffering a heart attack.
Studies have also shown that walking for 30 minutes a day can delay and possibly prevent the development of diabetes. People who are overweight have an especially high risk to develop this disease.
Walking strengthens the muscles and builds up the bones that they are attached to. Studies show that walking could decrease the risk of developing osteoporosis (骨质疏松症). Walking can also help ease the pain of arthritis in areas where bones are joined. This is because walking strengthens the muscles around the bones.
Experts say walking is one of the safest ways to exercise. There is a low risk of injuries. So it is good for people who are starting an exercise program for the first time and for older people.
A walking program is easy to start. You should wear loose clothes and good shoes. There are shoes that are designed especially for lots of walking.
How fast should you walk? For the best effect, doctors say you should walk fast enough to cause you to breathe hard. Yet you should still be able to talk. Let your arms move freely while you walk.
There are no rules to starting a walking program. You might walk short distances. Or you might walk up hills to strengthen your leg muscles. Health experts say you can gain the most from a walking program if you walk at about five kilogmeters an hour for 30 minutes a day. You should do this about five times a week.
                     
Walking to (小题1:)____________fit
(小题2:)____________ of walking
Superiorities to other exercises
Tips to walkers
Reducing the risk of a heart attack
                     (小题3:)___________the blood pressure
                     Raising good cholesterol
Being (小题4:)______ than many other ways of exercise, especially for (小题5:) ________or elders
Wear loose clothes and good shoes
Walk fast enough to cause you to breathe with (小题6:)________ but still able to talk
                   Controlling the development of diabetes
                     Help you lose weight
Walk with your arms move (小题7:)_________
Decreasing the risk of osteoporosis and arthritis
                 Strengthening the muscles
                     (小题8:)_______________ up the bones
Being easy to start (小题9:)___________ rules
 
Lowering the risk of other diseases, such as stroke, depression and etc.
 
题型:单项选择题
已知关于x的分式方程
2
x+2
-
a
x+2
=1
的解为负数,那么字母a的取值范围是______.
题型:单项选择题

中 * * 主义青年团团旗旗面为红色,象征()。

A、革命胜利

B、青春理想

C、蓬勃生命

D、年轻活力

题型:单项选择题

用心轴定位距法钻多孔时,不但要控制垂直方向上的距离,还要测量、控制对角斜边上上的距离。

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