公元533～公元544年中国北魏农学家贾思勰著（），全面地总结了秦汉以来中国黄河中下游的农业生产经验，其中含有丰富的生物学知识。
参考答案：《齐民要术》
In my opinion,all Mr White________good to his students in his class at present.He is very strict
in their study.[ ]
A. does does does
B. does do do
C. does does do
D. did do does
“便捷通关电子账册”的基本情况表内容发生改变的，只要未超出经营范围和加工能力，可以通过网络直接向海关申请变更。 ( )
