指向引线中基准线的虚线是画在基准线实线的下侧。( )
参考答案：错
如图所示，来自远方物体的光，经眼球折光系统折射后成像在A点，根据该光路图，这个人需配戴装有______镜的眼镜加以矫正．
Lucy is _____ good girl. She often helps others. [ ]
A. a
B. an
C. the
D. /
