填空题

Columbia
British Columbia is the third largest Canadian province, both in area and population. It is nearly one and a half times as large as Texas, and extends 800 miles (1,280 km) north from the United States border. (46) .
Most of British Columbia is mountainous, with long rugged ranges running north and south. (47) . During the last Ice Age, this range was scoured (侵蚀) by glaciers (冰川) until most of it was beneath the se

• a. Its peaks now show as islands scattered along the coast.
  The southwestern coastal region has a humid mild marine climate. Sea winds that blow inland from the west are warmed by a current of warm water that flows through the Pacific Ocean. As a result, winter temperatures average above freezing and. Summers are mild. (48) .
  (49) . As they rise to cross the mountains, the winds are cooled, and their moisture begins to fall as rain. On some of the western slopes almost 200 inches (500 cm) of rain fall each year.
  More than half of British Columbia is heavily forested. (50) . These forest giants often grow to be as much as 300 feet (90m) tall with diameters up to 10 feet (3m). More lumber is produced from these trees than from any other kind of tree in North America.A. On mountain slopes that receive plentiful rainfall, huge Douglas, firs (洋松) rise in towering columnsB. It includes Canada’s entire west coast and the islands just off the coastC. These warm western winds also carry moisture from the oceanD. Plants are the basis of the food pyramid for all living things, even for other plantsE. Even the coastal islands are the remains of a mountain range that existed thousands of years agoF. Inland from the coast, the winds from the Pacific meet the mountain barriers of the coastal ranges and the Rocky Mountains