等角正割圆锥投影图的纬线是（）。
A：直线
B：曲线
C：不同心的圆弧
D：以圆锥顶点为圆心的圆弧
参考答案：D
--- Julia hurt her back when she fell, and she is now in hospital.
--- Oh, really? I _____ know. I _____ go and visit her.
A．don’t; would
B．didn’t; will
C．don’t; will
D．didn’t; am going to
空心活动配水管柱目前最多能配注（）层。
A、二
B、三
C、四
D、五
