下列事件在历史上出现的先后顺序是( )
①东汉结束 ②刘备称帝 ③赤壁之战 ④孙权割据江东
A:①②③④
B:③②④①
C:④③①②
D:②④③①
生物体表现出隐性性状时;该性状的基因组成是( )
—How do you spend the coming May Day holiday?— I haven't decided. I wonder during the holiday.