Stromatolite
n. [地]叠层 ( 石 )
🗣️ 情景例句
They have to be here.
它们肯定就在这儿。
Three times a week I have to walk all the way to the gym for my Phys Ed class.
一周有三次，我为了参加体育课而必须走路到体育馆。
The woman immediately behind the two cars happened to be a learner.
紧跟其后的一辆车上的司机碰巧是个初学者，