<p>My class was given a set of multiple choice questions along with the answer key, and I understand most of them, but some of them I fail to understand. Can somebody explain them to me?</p>
<p>1) Many sceintists maintain that a rise in sea level has occurred in the last hundred years as a result of global warming. If this is true, which of the following factors best explains such a rise?
A. Increased precipitation
B. Increased cloud cover
C. Increased evapotranspiration
D. Thermal expansion of the ocean
E. Melting of permafrost</p>
<p>2) If the population of a country grows at a rate of approximately 5% per year, the number of years required for that population to double is closest to:
A. 5 years
B. 10 years
C. 15 years
D. 25 years
E. 35 years</p>
<hr>
<p>The answers are 1) D and 2) E.</p>
<p>Why would the 1st one not be E? I always thought that a big concern for global warming was the melting of ice caps which would in turn raise sea level? Why is is thermal expansion instead?</p>
<p>And for the 2nd, doubling time is 70/(growth rate %), so it would be 70/5 = 14%, which should be choice C. Did I do something wrong? Apparently, the answer's E.</p>
<p>Thanks in advance.</p>