Answer:
According to one estimate, stands of century-old forest now account for only 7% of forest cover in the United States (USDA-FS 2000). Since 1600, 90% of the virgin forests that once covered much of the lower 48 states have been cleared away.
Explanation:
Mount Baker-Snoqualmie National Forest, Washington
The Mount Baker-Snoqualmie forest is located in the Cascade mountain range in Washington state and is home to 644,000 acres of old-growth. Situated around an hour away from the Seattle metropolitan area, this forest is one of the most frequently visited in the country.
Answer:
Limestone areas are predominantly affected by chemical weathering when rainwater, which contains a weak carbonic acid, reacts with limestone. This causes the limestone to dissolve. Carbon dioxide from the respiration of animals (and ourselves) is one cause of increased carbon dioxide in the atmosphere.
Answer:
I think it will mean that the words of the question represent the key-words of your thesis. So you mustn't change the words of the question while writing your thesis