问题 填空题

近日福建福宁湾海域再次发生赤潮,这是福建海域今年第五次发生赤潮。赤潮形成的原因主要是由海水富营养化造成蓝藻的暴发,对于水产养殖业影响极大。

(1)从细胞结构的特点与复杂程度上看,蓝藻属于___________细胞;从生态系统的营养结构上看,蓝藻处于__________。夏季气温偏高是福宁湾海域蓝藻暴发的原因之一,从本质上看这是人为污染超过了福宁湾海域生态系统的_________。

(2)环保部门怀疑某工厂是污染源之一,并对其排污口进行了检测。检验员沿河顺流每隔100m取水样一次,依次编号为①~⑨(已知⑤号水样正对工厂排水口),对各水样进行了如下处理:首先,检测水样中的蓝藻数量(A组);然后,滤除水样中全部蓝藻后,每份水样分为三等份,编号B、C、D,其中B、C组分别添加适量的N和P元素,D组不添加;再在各组中加入等量的蓝藻,放置在阳光下若干天,最后检测水样中蓝藻量,统计数据如下表(蓝藻数量,单位:百万细胞/mm3)。请回答有关问题:

①.通过A组数据可以判断该工厂是污染源,依据是____________________。

②.进行B、C、D分组实验的目的是探究工厂排出的污染物主要是N含量超标还是P含量超标,其中D组起________作用,从实验结果可得出的结论是_________________。

答案

(1)原核    第一营养级    自我调节能力(或抵抗力稳定性)

(2)①.工厂排水口和下游河水中的蓝藻数量明显多于上游     ②.对照     工厂排出的污染物主要是P含量超标

单项选择题

When I was young, my parents ran a snack bar in our small town.

One evening in early April, my mother told me to fill in at the snack bar (1) a worker who had the flu. I told her I would mess it up, (2) I had never worked at the bar before. I (3) that instead of making money, I would end up owing it.

"You can do it, " said my mother, " (4) , you won’t get much business until lunch. "

"But I’ll never remember the orders, and I’m no good (5) money. Please, Mom, don’t (6) me. "

"Then I’ll help you", she said.

I shrugged my shoulders. I thought my mother’s (7) was a bad one, but I (8) .

When I got to the bar the next day, I found my mother was (9) . Because the weather that day was rainy and cold, people wanted hot snacks and drinks. (10) , I was really slow at taking the orders and making change. The line of people grew, and everybody seemed (11) , I was so nervous that my hands shook, and I (12) a cup into pieces. What a mess! Then my mother came to (13) me, and she also showed me how to make (14) If someone gave me $ 5 for something that cost $ 3.25, I handed over (15) quarters and a dollar and said, "75 cents makes four dollars, plus one dollar makes five. " Things went more (16) after that.

By the end of the day, I could remember orders, (17) the bill, and make change quickly with a smile. I was even a little (18) when the sun came out and dried up business. My mother said she was proud of me, and when she (19) that I work at the snack bar again next year, I did not even shrug. I was too busy (20) the restaurant I would open one day.

14()。

A. money

B. lunch

C. coffee

D. change

多项选择题