读“我国四大地理区域”图，回答下列问题

图A中，物体的长度是 ____cm；图B中，塑料挂钩的吸盘能“吸”在平滑的墙面上，是由于 ____的存在；图C中，正在发声的音叉将乒乓球弹开，说明声音是由物体 ____产生的；图D中，两个表面光滑的铅块相互压紧后会粘在一起，表明分子间存在 ____力．

增加：在缺词处加一个漏字符号（∧），并在其下面写出该加的词。

删除：把多余的词用斜线（\）划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意：1.每处错误及其修改均仅限一词；2.只允许修改10处，多者（从第11处起）不计分。

    I was sitting at my favorite table in a restaurant on last Sunday waiting for the food I had ordered to arrive. I suddenly found that Lin Ling, one of my classmate, worked as a waitress there. Honest speaking, it was great surprise for me to find her working there. As far as I know, she's from a richer family. What made her work there? I walked up to her but asked her the reason. When asking, she said, “I just want to earn some pocket money so that we can help some children in poor areas go back to school.” How a good girl! I should learn from her.