白描从（）开始演变为一种独立的绘画样式。（）
A.魏晋南北朝时期
B.隋代
C.唐代
D.宋代
参考答案：D
We'll go to the farm and help the farmers with the apple-picking if it ________ tomorrow. [ ]
A. won't rain
B. will be rainy
C. doesn't rain
D. isn't raining
传输线的主要功能是什么？
