The invention relates to swing flapper used to kill mosquito and fly.本发明涉及一种用于捕杀蚊蝇的蚊甩子.And theoretical basis is presented to further apply nozzle - flapper valve to two - stage electro - hydraulic servo valve .较快的响应速度;为进...
Psychometric tests can save organizations from grim and costly mistakes.心理测试能够使组织机构避免犯下损失惨重的大错。At the required level of visual verisimilitude, computer animation is costly.要使电脑动画的视觉效果达到要求的逼真程度，花费会十分昂贵。Coastal defence is ...