問題詳情

Famed for their high-elevation forests, the Appalachian Mountains sweep southfrom Quebec to Alabama. Highest in New England and North Carolina, this broad systemcovers more than 1,200 miles to form the rocky backbone of the eastern United States. LineThe Blue Ridge Mountains form a substantial part, 615 miles, of the far-reachingAppalachians. They begin as a narrow, low ridge in Pennsylvania, then slowly spreadand rise until they reach the height of 5,938 feet at majestic Grandfather Mountain inNorth Carolina. The Blue Ridge technically includes among its major spurs the GreatSmoky Mountains and the Black Mountains; Mount Mitchell, in the latter range, is at6,684 feet the highest peak east of the Mississippi River. Like the rest of the Appalachians,these mountains were once substantially higher and bolder. Their uplift was completedsome 289 million years ago, and they have been drastically eroded ever since.At one time, immense continental glaciers covered the land as far south as Pennsylvania.Although they did not spread over the Blue Ridge, plants and animals far beyond their reachbecame adapted to the cold. When the climate warmed and the ice melted, the cold-adaptedspecies retreated northward, surviving in the south only at higher, cooler elevations.Red Spruces and Fraser firs are remnants of the Ice Age, thriving in the higher elevationsof the Blue Ridge; and local belches, birches, and red oaks are typical of forests fartherto the north.Sharing the high peaks is another distinctive plant community. This is the "bald"—atreeless area covered with grass, or more commonly, with broad-leaved shrubs. Oftenlarge and vigorous, the latter include huckleberries, mountain laurel, and most especially,rhododendron, an evergreen shrub that blossoms in June and creates some of the mostspectacular wild gardens on Earth.
32. The word "sweep" in line 1 could best be replaced by which of the following?
(A) brush
(B) extend
(C) clear
(D) hurry

參考答案

答案：B
難度：適中0.666667
統計：A(0),B(2),C(1),D(0),E(0)

內容推薦

內容推薦