Famed for their high-elevation forests, the Appalachian Mountains sweep south
from Quebec to Alabama. Highest in New England and North Carolina, this broad system
covers more than 1,200 miles to form the rocky backbone of the eastern United States. Line
The Blue Ridge Mountains form a substantial part, 615 miles, of the far-reaching
Appalachians. They begin as a narrow, low ridge in Pennsylvania, then slowly spread
and rise until they reach the height of 5,938 feet at majestic Grandfather Mountain in
North Carolina. The Blue Ridge technically includes among its major spurs the Great
Smoky Mountains and the Black Mountains; Mount Mitchell, in the latter range, is at
6,684 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 completed
some 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 reach
became adapted to the cold. When the climate warmed and the ice melted, the cold-adapted
species 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 elevations
of the Blue Ridge; and local belches, birches, and red oaks are typical of forests farther
to the north.
Sharing the high peaks is another distinctive plant community. This is the "bald"—a
treeless area covered with grass, or more commonly, with broad-leaved shrubs. Often
large and vigorous, the latter include huckleberries, mountain laurel, and most especially,
rhododendron, an evergreen shrub that blossoms in June and creates some of the most
spectacular wild gardens on Earth.
【題組】32. The word "sweep" in line 1 could best be replaced by which of the following?
(A) brush
(B) extend
(C) clear
(D) hurry
寫作批改
VIP與詳解卡管理
私人筆記( 0 )