Georgia Science Grade 6

Chapter 21: Our Impact on Water and Air

CRCT Practice

1
Which type of pollution might come from this site?
<a onClick="window.open('/olcweb/cgi/pluginpop.cgi?it=jpg::::/sites/dl/free/0078778441/516730/cg.jpg','popWin', 'width=368,height=297,resizable,scrollbars');" href="#"><img valign="absmiddle" height="16" width="16" border="0" src="/olcweb/styles/shared/linkicons/image.gif"> (46.0K)</a>
A)point source pollution
B)nonpoint source pollution
C)acid rain
D)smog
2
Which is the largest source of water pollution in the United States?
A)sewage
B)metals
C)oil
D)sediment
3
Which substance in fertilizers can cause an overgrowth of algae?
A)carbon
B)nitrogen
C)hydrogen
D)oil
4
Which areas have the most smog?
A)urban areas
B)mountains
C)deserts
D)saltwater marshes
5
What is the estimated percentage of rivers with a pollution rating of good?
<a onClick="window.open('/olcweb/cgi/pluginpop.cgi?it=jpg::::/sites/dl/free/0078778441/516730/ch.jpg','popWin', 'width=388,height=345,resizable,scrollbars');" href="#"><img valign="absmiddle" height="16" width="16" border="0" src="/olcweb/styles/shared/linkicons/image.gif"> (47.0K)</a>
A)17%
B)38%
C)45%
D)53%
6
What percentage of lakes are polluted?
<a onClick="window.open('/olcweb/cgi/pluginpop.cgi?it=jpg::::/sites/dl/free/0078778441/516730/ch.jpg','popWin', 'width=388,height=345,resizable,scrollbars');" href="#"><img valign="absmiddle" height="16" width="16" border="0" src="/olcweb/styles/shared/linkicons/image.gif"> (47.0K)</a>
A)8%
B)45%
C)53%
D)50%
7
This term describes pollution from industrial outfalls or ditches.
A)point source pollution
B)nonpoint source pollution
C)runoff pollution
D)chemical pollution
8
What might happen if heated water is released to a body of water?
A)oxygen levels decrease
B)oxygen levels increase
C)pH decreases
D)pH increases
9
Acid rain has what affect on the pH of natural lakes and streams?
A)it increases the pH
B)it decreases the pH
C)it stabilizes the pH
D)it doesn't affect the pH
10
Which pollutant is removed by this device?
<a onClick="window.open('/olcweb/cgi/pluginpop.cgi?it=jpg::::/sites/dl/free/0078778441/516730/ci.jpg','popWin', 'width=131,height=219,resizable,scrollbars');" href="#"><img valign="absmiddle" height="16" width="16" border="0" src="/olcweb/styles/shared/linkicons/image.gif"> (10.0K)</a>
A)carbon monoxide from smog
B)acids from rain
C)particulates from industrial smoke
D)chemicals from run off
Glencoe Online Learning CenterScience HomeProduct InfoSite MapContact Us

The McGraw-Hill CompaniesGlencoe

Please read our Terms of Use and Privacy Policy before you explore our Web site. To report a technical problem with this Web site, please contact the Web Producer.