Use of English PRO

(0) STRETCHING (STRETCH) from Norfolk, Virginia, to Miami, Florida, the Atlantic Intracoastal Waterway is an (1) ............ (LAND) channel. It is used mainly by (2) ............ (RECREATION) boaters. The waterway is not (3) ............ (ESSENTIAL) to commercial shipping which relies strongly on it. The channel is maintained by the U.S. Army Corps of Engineers (USACE). The mission of USACE is to provide vital public engineering services in peace and war to (4) ............ (STRONG) our nation's security, energize the economy, and reduce risks from disasters. At Wilmington District headquarters in Wilmington, North Carolina, USACE surveys and maps the conditions of waterways in the (5) ............ (COAST) regions of North Carolina and south-central Virginia. USACE boats, equipped with (6) ............ (SOPHISTICATE) sonar, cross over sections of the Atlantic Intracoastal Waterway every day. The district's survey boat fleet consists of the Gillette, the Beaufort, and the Sanderson. They determine how deep the water is, and (7) ............ (HYDROGRAPHY) surveys, which are water surveys, are done every day. A GPS signal determines the location of where the survey is conducted, and the sonar equipment records the (8) ............ (DEEP) of the waterway at that point.