单项选择题
The depth over a shallow patch，（）about 1．5 miles southeastward of Nanshan Tou lighthouse，reduces to 8 meters.
A.lay B.lies C.being lain D.lying
单项选择题 The danger associated with using carbon dioxide in an enclosed space is（）.
单项选择题 The bottom row of plating next to the keel of a lifeboat is known as the（）.
单项选择题 The backup system on an electric start survival craft is a（）.
