题干

如图是利用人工湿地净化生活污水(主要含有机物)的原理简图.请据图回答:

(1)人工湿地是一个生态系统,其中芦苇、绿藻、黑藻属于____成分,芦苇属于挺水植物,绿藻属于浮游植物,黑藻属于沉水植物,这一现象体现了群落的____ 结构.

(2)要维持该生态系统的稳定,在该人工湿地生态系统中,除了以上生物群落外,还必须有____ 成分.与其他自然生态系统相比,该生态系统能量的不同之处是:多了____

(3)人工湿地可以净化生活污水,但对污水排放量要加以控制,其生态学依据是生态系统的____ 是有限的.

(4)人工湿地中的微生物往往是混杂生长的.人们在研究微生物时一般要将它们分离提纯,然后进行数量的测定.对微生物进行计数的常用方法包括____ 和显微镜直接计数.

(5)若一同学在稀释倍数为105的培养基中测得平板上菌落数的平均值为23.4,那么每毫升样品中的菌落数是____ (涂布平板时所用稀释液的体积为0.1mL).

(6)对一支试管中的培养液中的酵母菌逐个计数是非常困难的,可以采取的方法____ 

(7)在实验室提取胡萝卜素的时候,应选择____ 的加热方式,原因是____

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同类题3

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When they saw I didn't move, they quickly built a platform(平台) next to my head, and an official (官员) climbed up there to speak to me. Although I could not understand his language, I understood that they would be friendly towards me---if I did not try to harm (伤害) them. By now I was very hungry, so I used sign language to ask the official for food. He seemed to understand me, because they put ladders(梯子) against my sides and little men climbed up with baskets of food and drink. They were surprised at how much I could eat and drink. In just one mouthful(一口) I ate three of their meat dishes and three of their loaves of bread. I drank two of their barrels (桶)of wine, and was still thirsty, because that was only half a litre (1升). While they were bringing me food, I wondered whether(是否) to pick up some of the little men and throw them to their death. But I was afraid they would shoot at me again, and anyway I was thankful for their kindness in giving me food and drink, so I did not move.

After some time, another official climbed up to the platform and spoke to me. From his signs I understood that they were going to move me. The King of this country(which was called Lilliput) had ordered his people to carry me to the capital city. I made signs to ask whether I could be untied(松绑),but the official politely refused.

While I was eating, they had prepared a platform to carry me. The people of Lilliput are very clever with their hands. For me, five hundred men built a special wooden platform with twenty-two wheels. One thousand, five hundred of the King's largest horses pulled me to the capital. I did not know about any of this, because they had put some sleeping pills (安眠药) in my wine, and I was in a deep sleep.