【单选题】The angle between the flukes and the shank of an anchor is called the ______.
【单选题】The angle between the limiting positions is the angle between ( )
A.
the corresponding positions of the cranks when the rocker is located in the two extreme positions
B.
the two extreme positions of the coupler
C.
the direction of the static force transferred through the coupler and absolute velocity of the output link at the connected point
【单选题】The pressure angle is the angle between .
A.
the coupler and the output link
B.
the two extreme positions of the coupler
C.
the direction of the static force transferred through the coupler and absolute velocity of the output link at the connected point
【单选题】______is an angle at which a cargo settles in the hold of a ship,between the horizontal and the slope made by a bulk cargo such as grain or iron ore.
【单选题】________is the angle between relative wind and the chord.
【单选题】_________ is the angle between the airplane longitudinal reference and the horizontal plane.
【简答题】阅读下列材料
材料一:
其守城之具有火炮名“震天雷”者,铁罐盛药,以火点之,炮起火发,其声如雷,闻百里外,所围半亩之上,火点著甲铁皆透。——《金史》
材料二:
海商之舰,大小不等,大者五千料,可载五六百人;中等二千料至一千料,亦可载二三百人;余者谓之“钻风”,大小八橹或六橹,每舰可载百余人,风雨晦冥时,惟凭针盘而行。——南宋《梦梁录》卷12《江海船舰》
据材料一、二回答这一时期我国的另一项...
【单选题】2018年中央一号文件提出,保持土地承包关系稳定并长久不变,第二轮土地承包到期后再延长_____年。
【单选题】材料六 五千年中华文明成就辉煌,但在一定的条件下,也会成为中国向前发展的包袱。先民修筑了万里长城,抵御了北方游牧民族的侵扰,但也限制了自己的视野和对外交往。先民开凿了大运河,沟通了中国南北,但这对于封建统治者来说,主要是为了加强中央集权,满足了专制者游玩的需要。运河往来最多的是官吏们的游船和运送皇粮的漕船。中国拥有“四大发明”,这固然是中华民族的奇迹和骄傲,但是罗盘针可以导航亦可看风水;火药可以制...