这个短句的字面解释是“抛在半空的东西”，这是什么意思呢？请看对话：

    A: The buying momentum seems to have returned to the stock market. Do you have any recommendations?

    B: It’s a toss-up whether stock prices will go up or down over the days ahead. It’s better to wait until investors become more reasonable and then you can choose companies that are doing well in business and whose midterm financial report will look good.

    Note: People use the idiom to describe a situation where two possibilities are equally likely. No one is certain where the term “a toss-up” originated, although it is believed to be a direct reference to the act of flipping a coin. Coins with different designs on either side have been produced for thousands of years, and it is quite likely that this expression has its origins in ancient times.