【单选题】A( n)______shape has four straight sides at 90°to each other, two of which are much longer than the other two.
【单选题】已知圆锥截切后的正投影,则正确的侧投影是( )
【单选题】A(n) __________ shape has four straight sides at go to each other, two of which are much longer than the other two.
【单选题】已知圆锥截切后的正投影,则正确的侧投影是( ) A B C D
【单选题】Four long straight wires carry equal currents into the page as shown. The magnetic force exerted on wire F is:
【单选题】已知圆锥被截切后的正面投影和水平投影,则Δ SAB 确定的平面是( )。
【单选题】Her hair is _________ . [ ]
【单选题】已知圆锥截切后的正投影及水平投影,则正确的侧投影是( )