We can make mistakes at any age. Some mistakes we make are about money. But most mistakes are about people.
Why do we go wrong about our friends? Sometimes people hide their real meanings when they say something. And if we don't really listen, we miss the feeling behind the words. Suppose someone tells you, “You're a lucky dog.” That's being friendly. But “lucky dog”? There's a bit of envy(嫉妒) in those words. Maybe he doesn't see _it_ himself. But “lucky dog” puts you down a little. He may mean you don't deserve your luck.
      How can you tell the real meaning behind someone's words? One way is to take a good look at the person talking. Do his words fit the way he looks? Do his words agree with the tone(语调) of voice? His posture(姿态)? The look in his eyes? Stop and think. If you spend the minute thinking about the real meaning behind one's words, it may save another mistake.

把20g溶质质量分数为95%的酒精，稀释为溶质质量分数为50%的酒精，根据需加水的体积 （水的密度为1g/cm³），为了减少实验误差，最好选用量筒的量程为（   ）

二战前夕，非洲只有埃及、埃塞俄比亚、（  ）三个国家独立

近年来我国经济社会快速发展，从下图中可以看出（   ）