|
C. for others
D. for another
II.
完形填空。从
A
、
B
、
C
、
D
四个选项中，选择一个正确答案，并在答题纸上将所选答案的字母涂黑。（本大题共
15
小题，每小题
1
分，共
15
分）
Fill in each blank in the passage with the most likely answer. (15 points)
Most living things undergo two types of biological change during their lifetime. One is
26
, an increase in the size or efficiency of an organism. The other is aging, which involves a
27
in size or efficiency.
Sings of aging
28
in most people between the age of 30 and 40. Heredity (
遗传
) determines most of the ways a person changes while aging, but environment also
29
a role. All the senses decline with age. For example, the eyes cannot adapt
30
darkness, and they require brighter light for reading. In women especially, bones lose calcium(
钙
) and become more likely to
31
.
Many people believe that with advancing age, an individual loses the
32
to learn, remember, and make decisions. But
33
disease or injury damages the brain, a healthy elderly person
34
remains physically and mentally active probably suffers
35
serious decline in mental capacity.
No one fully understands the aging process. Some scientists
36
that human aging will ever be controlled. Others believe that aging can be conquered. They note that several species of fish continue to grow until death
37
any signs of aging. Normal human cells can be kept
38
in a laboratory for only a limited time. However, abnormal(
非正常的
) cells, such as various cancer cells, can live for a long time. If scientists can determine how
39
cells survive, they may gain an insight
40
the process of cell aging.
26. A. development
B. growth
C. progress
D. improvement
| 
