What advice is given for printing the signs according to the last paragraph?

A. Colored signs are preferred.

B. Bold letters should be used.

C. Large pictures should be included.

D. Phone numbers should be provided.
出自:河南城建学院-大学英语1

完成拼图验证

按住下方滑块,将拼图拖到缺口处后松开。

拼图背景,将小拼图拖到缺口处
向右拖动滑块