Every year the earth travels about 109km as it orbits the sun. what is earth's average speed in km/h?

109km per year seems strangely low, but oh well.

Convert years to hours.
1yr * 365days * 24hrs = 8760 hrs

You have all the data needed.  Divide by the following:
109km/8760hr = 0.01244 km/hr

It is false that during exercise, the oxygen concentration in the blood increases to twice that of resting levels. As a matter of fact, the oxygen either stays the same or decreases, or it may increase slightly than it used to be when the person was resting, but it definitely does not double while exercising. Hope this helps. Let me know if you need additional help!