Ddm
abbr. 调制深度差（Difference of Depth of Modulation）；分布式数据管理（Distributed Data Management）
🗣️ 情景例句
Would Ms Lin please come forward?
有请林小姐到前面来。
He who would climb the ladder must begin at the bottom.
爬梯必须从底层开始。
Haven't you met yet?
你们还没见面吗？