提醒：点这里加小编微信（领取免费资料、获取最新资讯、解决考教师一切疑问！）
The tallest living tree on record is a coastal red wood that was co-discovered in 2006 by naturalists Michael Taylor and Chris Atkins. Named Hyperion, their discovery took the title of world’s tallest tree from aredwood named The Tall Tree, which had previously held the record at 367.8 feet. Hyperion has been recorded at 379.3 feet and is still growing. Biologists and tree experts keep its exact location a secret in order to protect the ecosystem around the tree.
For many years, scientists were curious about what grew in the top of aredwood, but no one had ever been able to climb up in to the crown. Red wood branches begin 100 feet or more above the ground in an adult tree. The area where they start, called the crown, is a new frontier for scientists. Researchers used to believe that the crown was a fairly empty place. In fact, before the 1980s, researchers had to wait for a tree to fall to study it. Now, mountain climbing techniques and tools homes on the trees’ limbs. Science aredwood lives for centuries; we know that many of these ecosystems have been around for thousands of years. However, very little was known about them until recently.
One of the main scientific questions about these trees concerns water. How does a tree like Hyperion to send water to branches that are 250 feet above the ground?Under normal conditions, it can take two weeks for water to travel from the roots to the highest parts of the crown. However, coastal redwoods have another way to get water; they pull it directly from the air into their branches. In this way, the upper branches of the tress get the water they need to support a variety of plant and animal life.
Biologists have observed that other plants grow in the dead parts of tree. When a large branch dies, the tree simply redirects its energy to new grow thin other areas. The dead branch is still part of the tree, but as it rots, insects and other plants penetrate the deadwood and complete the process of creating a soil-like environment full of minerals. The deal places become gardens where new plants emerge.
No one knows how tall aredwood can actually grow or how long it can live. The red wood forests of California are smaller than the formerly were. Scientists assume that at reached400 feet andlivedfor4,000years, but they have yet to find one. Exists and is just waiting to be discovered.
24. From the text, we know the fact that ______.
A.aredwood can offer shelter for other plants
B. Aredwood will be protected once discovered
C.aredwood will live without water for 2weeks
D.a red wood can form a crown with falling branches
25. Which of the following best explains “redirects”underlined in the last paragraph but one?
A. Transforms B.Delivers C.Instructs D. Consumes
26. What does the author intend to tell us in the last paragraph?
A.More secrets of giant redwoods remain to be discovered.
B. Scientists expect a thorough exploration of redwoods in California.
C. The longevity of redwoods will become the next important research.
D.Research on redwoods should be based on the protection of environment.
提醒：点这里加小编微信（领取免费资料、获取最新资讯、解决考教师一切疑问！）
