Experimental study on 2bd - 7 type multifunctional precision seed spacing drill 7型多功能精密耕播机的试验研究
2.
Manufacture and study on precision furrowing and seeding machine 2bd - 7 type 7型多功能精密耕播机的研制与试验研究
3.
This tendency is particularly problematic because it rests upon the unproven or even untested assumption that changes in food 当然，这一假定的正确与否还有待于我们对农业的耕播前和收获后的行为做一番更为深入的考察。
