设等比数列{an}的公比q＜1，前n项和为Sn．已知a3=2，S4=5S2，求{
题型：填空题
问题：
设等比数列{an}的公比q＜1，前n项和为Sn．已知a3=2，S4=5S2，求{an}的通项公式．
题型：填空题
阅读理解。
Though its number is increasing ,the Hainan deer is not yet out of the woods of endangerment. That is , it is
in great danger.
The Hainan deer, or EId's deer, is found only in Hainan Province of South China. It looks similar to the sika
deer, but bears no plum flower spots on the body.
In the Datian Nature Reserve of Hainan the deer population has increased from 26 in 1976 to the present
500. But with the development of the island in recent years, the Hainan deer is faced with more serious
challenges to go on living.
The Datian Reserve is only 13 square kilometers in area, which is too small for the Hainan deer to find good
places or enough food.
Because more and more people have moved to the island and settled here, more land is used for building.
Weak deer which are driven out by their fellows are threatened by human neighbours. Illegal hunting is pushing
the valuable deer into difficult situation.
The Hainan deer is brown, with the female lighter in colour, and has a clear black line across the back. They
like to feed in bamboo forests, bushes and grassland under the rocks. They belong to herbivores, which feed on grass instead of meat.
From mid-January to June is the breeding season for the Hainan deer. The male deer fight against one
another with their antlers to determine the order to breed. The top winner has many more choices than the
others.
In September, the female deer start to bear fawns. The little deer follow their mothers until two years of age.
1. From the passage we know the Hainan deer _____.
A. has no antlers
B. has no plum flower spots on the body
C. is out of the woods of endangerment
D. hasn't increased since 1976
2. What makes the Hainan deer endangered?
A. More land is being developed.
B. The Datian Reserve is too small.
C. Illegal hunting.
D. All of the above.
3. During the period, from mid-January to June, the male deer fight against each other in order to _____.
A. get more choices to breed
B. get enough food
C. get good places
D. get more baby deer
4. The writer wrote this article mainly to ______ .
A. tell us that the number of Hainan deer is increasing
B. introduce us a most precious deer
C. let us know where Hainan deer live
D. warn us that the Hainan deer is endangered