The state of Vermont is known as green mountain state.
Contour lines determine the steepness of the land by how close they are together. Generally, contour lines rise to a particular scale (e.g. a line for every ten metres), therefore, if the contour lines are closer together then the height of that particular area has risen more steeply than if the contour lines are further apart where the steepness has increased more gradually.
These deep-ocean<span> currents are driven by differences in the </span>water's<span> density, which is controlled by temperature (thermo) and salinity (haline). This process is known as thermohaline </span>circulation<span>. In the Earth's polar regions </span>ocean water<span> gets very cold, forming </span>sea<span> ice.</span>
The best bibliogaphic entry would probably be: Smythe, Clark. <em>Unsinkable: Folly on the Titanic</em> Little, Brown: New York, 1976.
That is because it seems to be a book about the Titanic itself, whereas the other ones have to do with:
- topics which are less directly related to the subject-matter (the first entry is about maritime laws and the third one is about the animal and plant populations of the lands near the North Pole),
- personal, relative accounts of the events (like the fourth entry, which is an autobiography of a survivor and therefore describes the wreck through the character's own perspective) as opposed to more factual material.