共用题干 The first navigational lights in the New World were probably lighthouses hung at harbor en-trances.The first lighthouse was put up by the Massachusetts Bay Colony in 1716 on Little Brew-ster Island at the entrance to Boston Harbor. Paid for and maint

共用题干
The first navigational lights in the New World were probably lighthouses hung at harbor en-trances.The first lighthouse was put up by the Massachusetts Bay Colony in 1716 on Little Brew-ster Island at the entrance to Boston Harbor. Paid for and maintained by“light dues”levied（征收）on ships,the original beacon was blown up in 1776 .Until then there were only a dozen or so true lighthouses in the colonies.Little over a century later,there were 700 lighthouses.
The first eight lighthouses erected on the West Coast in the 1850s featured the same basic New England design:a Cape Cod dwelling with the tower rising from the center or standing close by .In New England and elsewhere,though,lighthouses reflected a variety of architectural styles.
Since most stations in the Northeast were set up on rocky eminences（高处）,enormous towers were not the rule .Some were made of stone and brick,others of wood or metal.Some stood on pilings or stilts;some were fastened to rock with iron rods.Farther south,from Maryland through the Florida Keys,the coast was low and sandy.It was often necessary to build tall towers theremassive structures like the majestic lighthouse in Cape Hatteras,North Carolina,which was lit in 1870.190 feet high,it is the tallest brick lighthouse in the country.
Not withstanding differences in construction appearance,most lighthouses in America shared several features:a light,living quarters,and sometimes a bell(or,later,a foghorn).They also had something else in common:a keeper and usually the keeper's family.The keeper's essential task was trimming the lantern wick（灯芯）in order to maintain a steady,bright flame. The earliest keepers came from every walk of life,they were seamen,farmers,mechanics,rough mill hands and appointments were often handed out by local customs commissioners as political plums.
After the administration of lighthouse was taken over in 1 852 by the United States Lighthouse
Board,and agency of the Treasury Department,the keeper corps gradually became highly professional.

It can be inferred from the passage that lighthouses in the Northeast did NOT need high towers because________.
A: ships there had high masts
B: coastal waters were safe
C: the coast was straight and unobstructed
D: the lighthouses were built on high places