During the Jurassic to Cretaceous period,between 170 and 140 million years ago,Hong Kong was the scene of violent volcanic activity. Thick accumulations of lava and ash were deposited.是什么意思_During the Jurassic to Cretaceous period,between 170 and 140 million years ago,Hong Kong was the scene of violent volcanic activity. Thick accumulations of lava and ash were deposited.在线翻译_英语_读音_用法_例句