1. The table indicates that N and O are the_____gases in the air.
a. least
b. major
c. best
d. minor
2. About one-fifth of air consists of______
a. nitrogen
b. oxygen
c. argon
d. carbon dioxide
3._______than 1% of the air consists of argon, carbon dioxide, neon and helium.
a. Least
b. More
c. Less
d. Most
4. The air is composed of different______
a. numbers
b. symbols
c. molecules
d. gases
5. The amount of nitrogen is_____compared to oxygen,
a. as significant as c. slightly significant
b. very significant d. not so significant​