That's true, when you waiting for somebody, you should turn off your car engine so it won't damage the environment
I didn't actually understand the question but I will try to solve it.
Length of ribbon = 3 ft
Total number of small pieces = 8
So, length of each piece = 3/8 = 0.375 ft
4. not enough
4. that's not enough coffee
5. the degree to which something has spread; the size or scale of something.
5. that was the extent of the conversation