【判断题】If there are two goods, and if one good has a negative price and the other has a positive price, then the slope of the budget line will be positive.
【判断题】If there are two goods and if one good has a negative price and the other has a positive price, then the slope of the budget line will be positive.
【单选题】听力原文:M: I ran all the way to the bus stop, but the man at the ticket counter told me the bus left only 5 minutes ago. W: That's too bad. Those buses leave only every 50 minutes. Q: How long does the m...