Emperor Qian Long's tone at the end of his letter is best described as straightforward and respectful. Here's why:
1. **Straightforward**: The Emperor communicates his message clearly and directly without using ambiguous language or beating around the bush. This indicates a straightforward tone in his writing.
2. **Respectful**: The Emperor maintains a tone of respect towards the recipient of the letter. He likely uses polite language and a formal style to show courtesy and honor towards the person he is addressing.
Therefore, the words "Straightforward and respectful" best describe Emperor Qian Long's tone at the end of his letter.
