In the last sentence of the first paragraph, seeing the Prime Minister off in Shili Long Street can give full play to your imagination and add some actions to enrich the description. Some possible actions include:

1. The masses waved national flags and flowers to show their warm welcome to the Prime Minister.

The student representatives presented their hand-made welcome cards to the Prime Minister to express their gratitude.

A group of students formed a choir and sang touching songs loudly to express their respect and blessings to the Prime Minister.

A child summoned up the courage to salute the Prime Minister and prayed that the Prime Minister would provide better educational conditions for their school.

Another child ran to the Prime Minister's side, greeted him cordially and paid tribute to the Prime Minister's contribution to the national education.

The above are just some imaginary action scenes that may happen, and the specific plot can be further created as needed.