Write and implement (test run) the following four SQL queries:

a. Return the date/time, station name and the highest recorded value of nitrogen oxide (NOx) found in the dataset for the year 2019.

b. Return the mean values of PM2.5 (particulate matter < 2.5-micron diameter) & VPM2.5 (volatile particulate matter < 2.5-micron diameter) by each station for the year 2019 for readings taken on or near 08:00 hours (peak traffic intensity). c. Extend the previous query to show these values for all stations in the years 2010 to 2019.