搜题请搜索小程序“爱下问搜题”
问题 实验题

图为草原生态系统的一部分。

（1）生态系统的组成包括                和                 。

（2）生态系统所需的能量最终都来自           ；在图中用箭头标出食物链中能量流动的方向。

（3）此生态系统中的生产者是          ，通过光合作用制作           ，释放           。

（4）写出图中的食物链：                                                      。

答案

（1）生物成分    非生物成分  （2）太阳    （3）青草       有机物      氧气

（4）青草→野兔→狐狸

题目分析：生态系统由生物部分和非生物部分组成，生态系统所需的能量最终来自于太阳光能。在生态系统的食物链和食物网中，能量总是沿着食物链和食物网流动。在生态系统中，生产者指绿色植物，绿色植物通过光合作用制造的有机物，产生氧气。食物链的第一种生物一定是植物，最后一种生物肯定没有天敌。所以图中的食物链为：青草→野兔→狐狸

单项选择题

I will never forget the year I was about twelve years old. My mother told us that we would not be (16) Christmas gifts because there was not enough money. I felt sad and thought, "What would I say when the other kids asked what I’ d (17) " Just when I started to (18) that there would not be a Christmas that year, three women (19) at our house with gifts for all of us. For me they brought a doll. I felt such a sense of (20) that I would no longer have to be embarrassed when I returned to school. I wasn’t (21) . Somebody had thought (22) of me to bring me a gift.

Years later, when I stood in the kitchen of my new house, thinking how I wanted to make my (23) Christmas there special and memorable, I (24) remembered the women’s visit. I decided that I wanted to create that same feeling of (25) for as many children as I could possibly reach.

So I (26) a plan and gathered forty people from my company to help. We gathered about 125 orphans (孤儿) at the Christmas party. For every child, we wrapped colorful packages filled with

toys, clothes, and school supplies, (27) with a child’ s name. We wanted all of them to know they were (28) Before I called out their names and handed them their gifts, I (29) them that they couldn’t open their presents (30) every child had come forward. Finally the (31) they had been waiting for came as I called out, "One, two, three. Open your presents!" As the children opened their packages, their faces beamed and their bright smiles (32) up the room. The (33) in the room was obvious, and (34) wasn’ t just about toys. It was a feeling, and the feeling I knew (35) that Christmas so long ago when the women came to visit. I wasn’t forgotten. Somebody thought of me. I matter.

21().

A. blamed

B. loved

C. forgotten

D. affected
查看答案
多项选择题

逐渐加重的颅内压增高，能引起下列哪项改变（）

A.脑血流量自动调节的损害

B.脑水肿

C.柯兴反应

D.脑疝

E.以上均不对
查看答案