What evidence is there to establish that the people of Mohenjodaro had a great concern for Sanitation and Town planning?

Read the following excerpt and answer the questions that follow:

"Although the script remains undeciphered, there is widespread consensus on the direction of writing in the script. Barring a few exceptions, the writing direction is predominantly right to left (i.e., left to right in seals and right to left in the impressions)."
(Source: https://www.harappa.com/sites/defau/t/files/pdf/The-/ndus-Script.pdf)

(a) What is the primary medium where Harappan script is found?

(b) Why is the Harappan script significant in understanding their culture?

Read the line given below and answer the question that follows:

"The discovery of lamp-posts at intervals reveals the existence of street-lighting."

(a) What does the presence of lamp-posts indicate about Harappan cities?

(b) Name two other public facilities provided in Harappan cities.

Why is the grid-patterned layout of Harappan cities considered a pioneering achievement in urban planning?