他给他演示如何吹奏象牙吹口乐器。He showed him how to blow into the ivory mouthpiece.象牙海岸成为世界上可可粉的主要产地。The Ivory Coast became the world's leading cocoa producer.象牙磨损的速度快于生长的速度。Elephants wear the tusk down faster than they can grow i...
Thin layers of sandy shale, and carbonaceous fragments are locally present.局部出现砂质页岩薄层和碳质碎屑.This sandstone unit is commonly thick - bedded and massive, with silty and carbonaceous laminations.该砂层单元通常为厚层或块状, 具粉砂质和碳质纹层.Beca...