Radioecho
无线电回波, 无线电反射信号
🗣️ 情景例句
going to the children's ward once or twice a week
每星期就去小儿科病房一、两次
I'm washing my hair in the bathroom.
我在浴室洗头。
Though Mr.Thompson had turned the lights off before he went to bed, they were on in the morning.
虽然汤普森临睡觉时把灯关了，但早晨灯却都亮着。