问题 综合

阅读图文资料,并结合所学知识回答下列问题。

人们在观察高山植被时发现,在不同海拔高度上,森林有着不同的种群和结构特征,在一个特定的高度上不再有森林的分布。在一个特定的区域内,理论上森林分布所能达到的极限高度就叫这个区域的林线高度。

(1)说出我国林线高度最高和最低值分别位于我国哪两个区域?(2分)

(2)简要描述我国林线高度的分布特征。(4分)

(3)从图中可看出我国南方林线高度比北方高,这是受什么因素影响形成的?这因素是如何影响林线分布高度的?(4分)

答案

(1)林线最高值位于青藏高原上,最低值位于我国领土最北端。   (2)林线高度从南向北逐渐降低(或从西南向东北递减)   (3)纬度因素(热量)   低纬度地区热量充足,与同样高度的高纬度地区相比,有更多热量能满足森林生长的需要,所以南方林线高于北方。

(1)从图中看,我国林线最高值位于青藏高原上,最低值位于我国领土最北端。(2)从图中看,我国林线高度从从西南向东北递减(或南向北逐渐降低)。(3)我国南方林线高度比北方高,这是受纬度因素(热量)影响形成的,因为低纬度地区热量充足,与同样高度的高纬度地区相比,有更多热量能满足森林生长的需要。

单项选择题
单项选择题

I was a single parent of four small children, working at a low paid job. Money was always tight, but we had a (1) over our heads, food on the table, clothes on our backs, and if not a lot, always (2) . Not knowing we were poor, my kids just thought I was (3) . I’ve always been glad about that.

It was Christmas time, and although there wasn’t (4) for a lot of gifts, we planned to celebrate with a family party. But the big (5) for the kids was the fun of Christmas (6) .

They planned weeks ahead of time, asking (7) what they wanted for Christmas. Fortunately, I had saved MYM120 for (8) to share by all five of us.

The big (9) arrived. I gave each kid a twenty-dollar bill and (10) them to look for gifts of about four dollars each. Then everyone scattered. We had two hours to shop; then we would (11) back at the "Santa’s Workshop".

Driving home, everyone was in high Christmas spirits, (12) my younger daughter, Ginger, who was unusually (13) . She had only one small, flat bag with a few candies—fiftycent candies! I was so angry, but I didn’t say anything (14) we got home. I called her into my bedroom and closed the door, (15) to be angry again. This is what she told me.

"I was looking (16) thinking of what to buy, and I (17) to read the little cards on the ’Giving Trees’. One was for a little girl, four years old, and all she (18) for Christmas was a doll. So I took the card off the tree and (19) the doll for her. We have so much and she doesn’t have anything. "

I never felt so (20) as I did that day.

13()

A.quiet 

B.excited 

C.happy 

D.ashamed