据第六次全国人口普查结果显示，重庆常住人口约为2880万人。将数2880万用科学记数法表示为（ ） 万。
☆÷○=8……5，○最小是[ ]
A．4
B．5
C．6
D．7
An analyst does research about liquidity. Liquidity in financial markets is best described as the ability to purchase or sell an asset:（）
A. at a low transaction cost.
B. quickly at a known price.
C. quickly and easily at a price close to fair market value.
