Satellorb
模拟人造卫星的观察与研究气球
🗣️ 情景例句
Hi, Son. Is everything all right?
嗨 ，孩子 一切都顺利吗？
It's easy for me!
这简单！
If they knew how difficult it was to drill through the hard rock, they would lose heart.
如果他们知道了钻透那坚硬的岩石有多么困难，他们会丧失信心的。