如图所示的四种现象中，由于光的直线传播形成的是
答案：C
AD、反射现象，B、折射现象C、光沿直线传播，选C
What difficulty I had _____ the dirty walls! I had no choice but to have it ____ again.
A．clean, paint
B．cleaning, painting
C．cleaned, to paint
D．cleaning, painted
地机穴位于（）
A.胫骨内侧面后缘，内踝尖上5寸
B.胫骨内侧髁下方凹陷处
C.胫骨内侧面中央，内踝尖上5寸
D.胫骨内侧面中央，内踝尖上7寸
E.内踝尖与阴陵泉穴的连线上，阴陵泉下3寸
