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已知泡菜中亚硝酸盐含量与泡制时间有关。为了测定不同泡制天数泡菜中亚硝酸盐的含量,某同学设计了一个实验,实验材料、试剂及用具包括:刻度移液管、比色管、不同浓度的亚硝酸钠标准溶液、亚硝酸盐的显色剂、不同泡制天数的泡菜滤液等。回答相关问题:
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    My best friend Jenny and I got to the mall for shopping.She held up a white sweater and matching skirt.“Do you like this?”she asked.

    “It's great,''I said.Jenny nodded and continued looking while I moved about.touching the beautiful clothes.“ I'll try this on.”Jenny walked towards the dressing room.After a while,she came out in the outfit(一套衣服).She looked beautiful.

    I sighed. Part of me wanted to say how good she looked, but another part stopped the words coming out.Jenny was in such good shape that she'd look good in the outfit.Sometimes, I regretted choosing a best friend who was so pretty.God,why can't I be the one with the rich parents and the great look?More and more, I was envious(妒忌的)of her.

    “Well,Teresa,what do you think?”Jenny asked more than once.“Do you like it?''

    The outfit looked great on her,but I lied,“Not really.I think you need something with more colors.''

    “You think so?"Jenny said doubtfully.

    “Just believe me.We'll find something better,"I told her,pushing her back into the dressing room.“You just can't buy the first thing you see.”I did my best to get Jenny out of the store,away from that outfit.As we left,Jenny gave the sweater one last look.

    Just down the mall,we passed a yogurt place."My treat,''Jenny said,pulling out her wallet.

    I could never say no to chocolate,so we got some and sat down at a table.As Jenny talked without stopping about a million things,I thought about my feelings toward her.Those feelings weren't kind.

    Sitting there,  ▲  Jenny was attractive(吸引人的)not just because of her good luck,but more because of her kindness.Treating me to chocolate was far from her only show of generosity.She also let me drive her car and borrow her colothes.

    Finishing our chocolate,we headed for the next clothing store. "Look at that red sweater.''Jenny said as we passed the window."It would be perfect for you.Soon maybe you'll have enough by saving your babysitting money to buy something like that.”

    A few minutes earlier,all I had heard was about saving my babysitting money.I had hated the fact that Jenny could ask her parents for anything,and they'd buy it for her.This time,though.I heard more.I heard the voice of someone who loved and cared me for who I was.I needed to express the same to her.