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【单选题】
以玉米为主食的地区居民容易发生______缺乏病。A.
叶酸
B.
维生素A
C.
烟酸
D.
核黄素
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皮皮学刷刷变学霸
举一反三
【单选题】According to Mr. Hall, what is opportunity cost?
A.
It is the relationship between two kinds of goods or services that customers may want to buy.
B.
It is people's choice of goods and services at similar prices.
C.
It is the relative value of goods to buyers compared to the value of alterative goods and services on which they may want to spend that same amount of money.
【简答题】What is opportunity cost and how opportunity comes out?
【简答题】What is Opportunity Cost?
【简答题】CTP是由______转变而来，dTMP是由______转变而来。
【简答题】What is opportunity?