【简答题】求由摆线x=a(t-sint),y=a(1-cost)的一拱(0≤t≤2π)与横轴所围成的图形的面积.
【简答题】求由摆线 x = a ( t - sin t ) , y = a (1 - cos t ) 的一拱 (0 £ t £ 2 p ) 与横轴所围成的图形的面积 .
【单选题】—Were there ___ sharks in the aquarium? —No, there weren't _____. [ ]
【判断题】RFID技术、传感器技术和嵌入式智能技术、纳米技术是物联网的基础性技术
【单选题】According to the statistics, among the homeless in New York there were ______.
A.
more people in families than single persons
B.
about six thousand families
D.
more families with two parents than one
【判断题】电源表面是铁壳,所以在防静电布过小的时候,允许放置在防静电区域外。 ( )
【单选题】―Were there any sharks in the aquarium? ―______. [ ]
【单选题】我国10kV及以上电压等级的电力用户,供电电压正常允许的偏移范围是额定值的
【单选题】--- ___________ there any sharks in the aquarium? --- No, we didn’t see any.
【单选题】— Were there any dolphins in the aquarium? — ___________. We didn't see any in it. [ ]