题干

已知β锂辉矿(主要成分为LiAlSi2O6,还含有FeO、MgO、CaO等杂质),下面是以锂辉矿为原料来制取金属锂的一种工艺流程.

已知:①部分金属氢氧化物开始沉淀和完全沉淀时的pH:

氢氧化物

Fe(OH)3

Al(OH)3

Mg(OH)2

开始沉淀pH

2.7

3.7

9.6

完全沉淀pH

3.7

4.7

11

②Li2CO3在不同温度下的溶解度如下表:

温度/℃

0

10

20

50

75

100

Li2CO3的溶解度/g

1.539

1.406

1.329

1.181

0.866

0.728

请回答下列问题:

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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.