Some people want to exercise and wish to be outdoors and do something that will be good to the e_________ at the same ti

Some people want to exercise and wish to be outdoors and do something that will be good to the e_________ at the same time.
We also get 15-minute b_____ in the morning.
The afternoon is e______ since I have only two classes.
Mr Rudolph is really cool because he knows everything about history，and he tells us lots of interesting s_______.