学会与老师交往

    最近，对于八年级的李军来说是漫长而难熬的。妈妈生病住院了，他在家里既要做饭做家务，又要照顾年幼的弟弟，还要抽空去医院陪妈妈，往往连作业也顾不上写。期中考试结束了，李军知道自己考得不理想，但心里很想尽早知道自己的成绩。犹豫再三，他还是来到了班主任刘老师的办公室。李军说：“老师，我这次考试的成绩怎样？”刘老师说：“平时不好好用功，现在还有脸问我？”

用所给单词的适当形式填空，未提供单词的根据上下文填入适当的词。Mary's secret

Mary got home very late these few months. Her parents were very  ____ (worry). But when they asked

Ker about that, Mary always had different  ____ (excuse). Her father wanted to find out ____ happened to her.

One day after school, Mary's father secretly followed her to a park. Mary sat down ____. began to paint a picture alone. Her father, stood far away and watched her ____ (paint).

“This little girl comes here to paint every day. I think she  ____ (love) painting,” the cleaner there told him. Her father felt sorry, because he had never wanted ____ (understand) what his daughter liked. He and his wife thought painting was____ waste of time and never supported her. They thought Mary should focus more  ____ her studies, especially science. They only wanted to make her a doctor or an engineer. Now he realized what Mary liked

____ (much) of all her subjects. Her father was moved and changed his mind.

a．配制一定比例的浓H₂SO₄与浓HNO₃的混合酸，加入反应器中；

b．向室温下的混合酸中逐滴加入一定量的苯，充分振荡，混合均匀；

c．在55℃～60℃下发生反应，直至反应结束；

d．除去混合酸后，粗产品依次用蒸馏水和5% NaOH溶液洗涤，最后再用蒸馏水洗涤；

e．将用无水CaCl₂干燥后的粗硝基苯进行蒸馏，得到纯净硝基苯．

请填写下列空白：

①配制一定比例的浓H₂SO₄和浓HNO₃的混合酸时，操作的注意事项是：____．

②步骤d中洗涤、分离粗硝基苯应使用的仪器是____．

③步骤d中粗产品用5% NaOH溶液洗涤的目的是____．

④制备硝基苯的化学方程式____．