A topographic map. Two thick red lines go through areas with index contour lines with numbers 450 and 500. A thin black line with hashes goes through areas with index contour lines with number 450. Which value is a good estimate of the railroad’s average elevation?

450
480
500
550

This is all you, but i can give you some topics that you could try. if it rained when you want to do something outdoors, it 'limits' that human activity. maybe you want to do an experiment that goes throughout the whole year and you have to have above freezing the entire year. this 'limits' your activity. i thought of those just off of the top of my head. something that gets to me that might be getting to you is you are thinking too hard about what to do. think simply, and if it is too simple, then bump it up just a little bit.

How many miles is each lap?

Answertill;

The correct answer is (a.) in the coming years, the reyes family will save money because solar power requires little maintenance, and the energy used is free.