1.They gave nearly 2 million dollars to help the country with its national debt.
national debt 国债
He talked about the importance of reducing the national debt.
他谈了减少国债的重要性 。
2.The 2 million dollars is just a drop in the ocean compared to the country's 251 billion dollars debt.
a drop in the ocean 沧海一粟;九牛一毛
Compared with the boundless universe, we are only a drop in the ocean.
和无限的宇宙相比,我们只是沧海一粟 。