题目

We take most of our photos when we travel, but teens from Massachusetts, US, took photos of every corner of their own communities(社区). And they found things they didn’t know before. It’s part of a program to ask teenagers to care about the safety of their communities. They took photos and found problems.“I found I was a photographer and I wanted to show people what I saw,” said Faith Blass, 15. Blass found some leaves with holes burned by cigarettes on a street, which expresses a possible smoking problem among teenagers.“Even though I’ve lived in Somerville, from this program I如下图所示，甲图表示胚芽鞘受到单侧光的照射，乙图表示不同浓度生长素溶液对胚芽鞘生长的影响，如果甲图中b处的生长素浓度为m，设a处的生长素浓度为x，则(　　) A．m<x<n                    B．x＝i C．n<x<i                    D．x>i