题干

在农业生产中,农户常用一定浓度的萘乙酸(生长素类似物)除去与单子叶农作物混生的双子叶杂草.下图表示不同浓度的萘乙酸对单子叶植物和双子叶植物的影响,请据图分析回答:

(1)由图分析可知,萘乙酸对植物生长的作用具有两重性,即低浓度____,浓度过高则____ 

(2)当萘乙酸的浓度为B时,对曲线①和②的作用分别是____ .

(3)图中代表单子叶农作物的曲线是____ (填序号).

(4)田中所施萘乙酸的浓度最好在图中____ (用字母表示)之间.

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促进生长,抑制生长,促进、促进,②,C~D

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    Going green seems to be a fad(时尚) for a lot of people these days. Whether that is good or bad, we can't really say, but for the two of us, going green is not a fad but a lifestyle.

    On April 22, 2011, we decided to go green every single day for an entire year. This meant doing 365 different green things, and it also meant challenging ourselves to go green beyond easy things. Rather than recycle and reduce our energy, we had to think of 365 different green things to do and this was no easy task.

    With the idea of going green every single day for a year, Our Green Year started. My wife and I decided to educate people about how they could go green in their lives and hoped we could show people all the green things that could be done to help the environment. We wanted to push the message that every little thing counts.

    Over the course of Our Green Year, we completely changed our lifestyle. We now shop at organic(有机的) stores. We consume less meat, choosing green food. We have greatly reduced our buying we don't need. We have given away half of what we owned through websites. Our home is kept clean by vinegar and lemon juice, with no chemical cleaners. We make our own butter, enjoying the smell of home-made fresh bread. In our home office anyone caught doing something un-green might be punished.

    Our minds have been changed by Our Green Year. We are grateful for the chance to have been able to go green and educate others. We believe that we do have the power to change things and help our planet.