Subfluvial
水下的; 河底的
🗣️ 情景例句
We'll head down there first thing tomorrow morning.
明早第一件事就是去那。
It's about time to get up.
差不多该起床了。
may have left an automatic messenger behind to await the possible awakening of an advanced civilization.
很可能会在离开太阳系时留下自动化信息装置，等待先进文明的觉醒。