多项选择题 ‍篆书作为正体文字的朝代是（       ）​

多项选择题 He works in our university as a visiting _______, not as a formal faculty member.选项错误的是 A. traditional B. scholar C. nurse D. pilot

单项选择题 距今( )亿年前,寒武纪“生命大爆炸”,出现了三叶虫、腕足类等最早的生命体。 A. 5 B. 6 C. 7 D. 8