一会儿天阴得很黑;紧跟着就是打雷打闪.Pretty soon it darkened up and begun to thunder and lighten.一天傍晚, 突然下起可怕的暴风雨,又响雷又打闪.One evening a fearful arose, it thundered and light end.恐怕暴雨即将来临, 您看见那边打闪了 吗 ?I feel a thunderstorm is brewing. Do yo...
这些濒临灭绝的、性情温顺的大型动物属于高度群居的动物。These endangered gentle giants are highly social animals.贝茨看起来像个性情温和的小伙子。Bates looks like a good-natured lad.性情温和的斯坦利变了，成了充满信心、笑口常开的英雄。Mild-mannered Stanley morphs into a confident, grinning he...
分析了滚珠丝杠副的原理及结构形式.The rule and the composition of the ball screws were analyzed.给出四方向等载荷型哥德式沟槽直线滚动导轨副的装配关系.Assembly has a great influence on the quality of high precise linear motion rolling guide.在球面连杆机构中, 所有的转动副的轴必在一点上相...