Week 22: The last letter of the Greek alphabet is?
D – Omega http://www.ducksters.com/history/ancient_greece/greek_alphabet.php
D – Omega http://www.ducksters.com/history/ancient_greece/greek_alphabet.php
C – Continental glaciers http://www.onegeology.org/extra/kids/earthprocesses/continentalGlaciers.html
D – All of the above https://climate.ncsu.edu/edu/k12/.humidity
D – Australia https://en.wikipedia.org/wiki/Continent
C – Geographic grids http://web.csulb.edu/~rodrigue/geog140/lectures/geographicgrid.html
C – A Seismograph http://www.thefreedictionary.com/seismograph
B – Neil Armstrong http://www.nasa.gov/audience/forstudents/k-4/stories/first-person-on-moon.html
B – Common salt https://en.wikipedia.org/wiki/Salt
B – Nitrogen http://scied.ucar.edu/shortcontent/earths-atmosphere
D – Hummingbird https://www.quora.com/Can-birds-fly-backward