They controlled for changes due to social and cultural factors to calculate how strongly natural selection is shaping these traits.
研究小组严格控制了社会及文化因素引起的差异，以便单纯研究自然选择对这些特征的选择性到底有多强。
2
This paper introduces hydraulic vibration-exciting system for marble moulding machine, and pats forward rational selection method of vibration. parameter for the system controlled by rotary valve.
The whole digit-controlled lathe of lower prices generally choose stepping drive unit price is higher, and the machine tool selection servo drive unit.