what was the most expensive resources have you used

Question: what was the most expensive resources have you used
- Keywords:
  expensive,
  resource
Asked by anon-176026 to Paul on 22 Jun 2018.
- Paul Newell Price answered on 22 Jun 2018:
  
  The most expensive resources we use are the people. In other words the researchers and field team that do the work on our field experimental platforms. Our most expensive bit of equipment is the machine that measures a gas called nitrous oxide (laughing gas). We measure this because it is a very strong ‘greenhouse gas’ that can change our climate if there is too much of it in the air. It is 300 times stronger than carbon dioxide, the gas that we breathe out and that is given off when we burn fuels.

Question: what was the most expensive resources have you used