abbr. signaling and supervision techniques study 信号传送与监听技术研究; space surveillance and tracking satellite 空间监视与跟踪卫星; space-based surveillance and tracking system 天基监视与跟踪系统
🗣️ 情景例句
I've been thinking.
我一直在考虑。
None preaches better than the ant, and she says nothing.