The U.S. trade deficit narrowed sharply to $38.6 billion in December, the lowest in two years, because exports rose while imports plunged, a government report showed Friday. The trade deficit fell nearly 21 percent in December from November to $38.6 billion, the Commerce Department said. Exports rose 2.1 percent to $186.4 billion, the department said. Exports of oil and other petroleum products rose to the highest level on record. Overseas shipments of agriculture goods and aircraft also increased. Imports shrank 2.7 percent to $224.9 billion, the department said. Oil imports plunged to 223 billion barrels, the fewest since February 1997. A narrowed trade gap strengthens growth because it means U.S. companies earned more from overseas sales while consumers and businesses spent less on foreign products.