S-r
abbr. learning stimulus-response learning 学习刺激—响应学习; send-receive 发射-接收
🗣️ 情景例句
How nice to meet you.
认识你真高兴。
Beard the lion in his den.
老虎头上捉虱；太岁头上动土。
The tunnel would be well-ventilated if tall chimneys were built above sea level.
隧道就具备了良好的通风条件。