Approximately what percentage of the world's economies experience scarcity? ()
A. 10%
B. 40%
C. 85%
D. 100%
Which of the following is correct? ()
A. The word economy comes from the Greek word for “rational thinker.”
B. Economists study the management of scarce resources.
C. Because economists believe that people pursue their best interests, they are not interested in how people interact.
D. All of the above are correct.
浏览器不支持音频1+1=？
A. 1
B. 2
C. 3
D. 4
三图投影规律:主视图和俯视图之间______ ,主视图和左视图之间______ ,俯视图和左视图之间______ 。
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