In a code language, 'grass is green' is written as 'pp rr tt', 'vegetables are green' is written as 'rr dd ee', and 'bamboos are grass' is written as 'pp dd mm'. What is the code for the word 'vegetables' in that language?

Let's find the code by comparing the sentences:
'grass is green' = 'pp rr tt'

'vegetables are green' = 'rr dd ee'

'bamboos are grass' = 'pp dd mm'

Comparing (1) and (2): The common word is 'green' and the common code is 'rr'. So, green = rr.

Comparing (2) and (3): The common word is 'are' and the common code is 'dd'. So, are = dd.

Now looking at sentence (2): 'vegetables are green' → 'rr dd ee'.
We know green = rr and are = dd.
The remaining word is 'vegetables' and the remaining code is 'ee'.

Thus, the code for 'vegetables' is 'ee'.