four: n.1.四人小组;(套在车上的)四匹马。2.四的记号;(骰子的)四点;(钟点的)四时;四岁。3.〔pl.〕 四厘公债。4.(口)四桨小艇;四桨小艇艇员;〔pl.〕四桨小艇竞赛。5.〔pl.〕 【军事】四路纵队。6.〔pl.〕【机械工程】四汽缸发动机;四汽缸汽车。短语和例子a column of fours 四路纵队。 a child of four 四岁的孩子。 four-
Design and key technique of model ls4 - 2000a straight side four point press with multi - link have been introduced and the advantages and economic benefit of such machine have been expounded with comparison of other presses 摘要介绍了ls4 - 2000a型闭式四点多连杆压力机的设计和关键技术,并通过与其他压力机比较,阐述了其先进特点和较好的经济效益。