【多选题】下面哪些性质是中心投影法和平行投影法共有的基本性质( )。
【判断题】卷材面层根据材质可分为:塑料地面、橡胶地面、地毯、木质地面。
【多选题】下面哪些性质是中心投影法和平行投影法共有的基本性质( )。
【简答题】正方形ABCD中,AB=1,AB在数轴上,点A表示的数是-1,若以点A为圆心,对角线AC长为半径作弧,交数轴正半轴于点M,则点M表示的数是______.
【简答题】经过点M(2,2)作直线L交双曲线x 2 - y 2 4 =1于A,B两点,且M为AB中点 (1)求直线L的方程; (2)求线段AB的长.
【单选题】Geothermal resources, wind turbines, and hydropower facilities in Paragraph 4 cited as examples to illustrate that __________. 查看材料
A.
the amount of alternative energy production from public lands is huge
B.
alternative energy production is no less than conventional energy production
C.
they are the most typical conventional energy resources from public lands
D.
geothermal resources are more important than the other two
【单选题】The function of a hydropower station is to .
A.
Convert potential energy into electric energy;
B.
Convert electric energy into potential energy ;
C.
Convert water energy into electric energy.
【多选题】下面哪些是平行投影法特有的基本性质( )。