Which of the following requires an aditional intake of oxygen for a 20 to 30 minute period?
a. aerobic exercise
b. anaerobic exercise
c. flexibilty exercisie
d. high endurance exercise

Where would you expect to see seedless plants, such as ferns and mosses? a. in a botanical museum, because they are all extinct b. low and close to the ground in a moist environment c. climbing high while circling the branches of another plant d. deeply rooted in a forest with a trunk that reaches 20 meters or more

Consider the model of the oxygen cycle on earth. the majority of earth's oxygen reservoirs are found in the a) atmosphere. b) biosphere. c) hydrosphere. d) lithosphere.

Which entry is in the wrong position in the table?