光学大气质量与太阳天顶角有关。当太阳天顶角为0度时,大气质量为1;天顶角为48.2度时,大气质量为();天顶角为()度时,大气质量为2。
参考答案:1.5;60
Would you please supply ______ a complete set of catalogues for textile accessories so that we may make choice and work on them.
A.usB.us withC.us by D.us for
常见隔离开关的操动机构有()机构。
A.手动
B.电动
C.弹簧
D.液压