Answer: The answer choices on the left go with oceanography,
the ones on the right go with geography
Explanation: the ones on the left are about water, the ones on the right are about the Earth.
There have been 5 mass extinctions in the history of Earth, the main two are the K-T extinction (75% of the world organisms were killed) and the great paleozoic extinction. Scientists believe a massive meteorite caused the KT extinction but could also have been caused by some traps in India. The paleozoic extinction was believed to be caused by traps in Siberia which effected the temperature and atmospheric conditions of the tune
<span>The nitrogenous base pairs, which are linked by hydrogen </span>bonds<span> that also </span>hold<span> the </span>strands together<span>, are between this backbone.
There are 3 hydrogen </span>bonds <span>between guanine and cytosine.</span>