系统总结了6世纪以前黄河流域中下游地区农牧业生产经验以及食品加工与驻藏、野生植物利用等技术的农书是（）
参考答案：齐名要术
已知[X/2]补=0C6H，且该计算机的字长为8位二进制编码，则[X/4] 补= (19) 。
A．8CH
B．18H
C．0A3H
D．0F1H
According to the speaker, it is foolish and childish for a filmmaker to mix his preconceptions with objective truth when he produces a documentary.
