Christobalite
方英石
🗣️ 情景例句
we need to put together volunteers
我们需要募集义工
The population of Africa is growing by leaps and bounds.
非洲的人口正在极其迅速地增长。
The undulating waves of the open sea are generated by three natural causes:
海浪是由三个自然因素形成的：