Isotopes
n. 核素；同位素（isotope的复数）
🗣️ 情景例句
I'll have her call you as soon as she comes back.
等她一回来， 我就请她马上回电。
The first step is the only difficulty.
万事起头难。
Then the sound of rumbling thunder reached the watchers on the shore, as cargo, ballast,
岸上的观众听到船上发出了雷鸣般的轰响。当物品、压舱物、