·2,447,543篇论文数据，部分数据来源于NoteExpress
"Flap" sounds like something (a flag, a sail) flapping, and "flop" is the dull sound of something falling down flat.
而flop听着就象什么东西直直落地发出的沉闷一响.
youdao
应用推荐
模块上移
模块下移
不移动