【单选题】数据库概念设计的E-R方法中,用属性描述实体的特征,属性在E-R图中,一般使用如下所列的表示。
【简答题】为了减弱垂直轴倾斜误差的影响,观测过程中应保持照准部水准器气泡居中。当使用J1型和J2型经纬仪时,若气泡偏离水准器中央一格时,应在测回间重新整平仪器,这样做可以使观测过程中垂直轴的倾斜方向和倾斜角的大小具有(),可望在各测回观测结果的平均值中减弱其影响。
【单选题】Without proper planning, tourism can cause problems. For example, too many tourists can crowd public places' that are also enjoyed by the inhabitants of a country. If tourists create too much traffic,...
A.
It is extremely important to develop tourism
B.
Building roads and hotels are essential
C.
Support facilities are highly necessary
D.
Planning is of great importance to tourism
【判断题】为了减弱垂直轴倾斜误差的影响,观测过程中应保持照准部水准器气泡居中。当使用J1型和J2型经纬仪时,若气泡偏离水准器中央一格时,应立即重新整平仪器并重测本测回。
【单选题】一个样本中所包含的个体数目是多少是指( )。
【简答题】为了减弱垂直轴倾斜误差的影响,观测过程中应保持照准部水准器气泡居中。当使用J1型和J2型经纬仪进行精密角度测量时,若气泡偏离水准器中央一格时,应立即重新整平仪器并重测 。
【单选题】一个样本中所包含的个体数目是多少是指( )。
【单选题】The Planning Office had decided to close the school because ______.
A.
there were too many children in each class
B.
the schools in Raval were bigger and better
C.
it had too few children and it was expensive to run
D.
the teacher was retiring and they could not find another