Alice was very worried about her dad. For some time now she had noticed he was 1 his hair. One day, she asked him, “Daddy, every day you have less hair.2 is that?” Her father smiled and said, “It's the hair thief. He visits my head during the night when I'm 3. One by one he 4 out my hair, as much as he likes.”

    This worried Alice but she was 5 to help her father. That very night she stayed 6 as long as she could. When she was 7 her dad and mom had fallen asleep, she took a hammer and went straight to their bedroom. She walked carefully in order not to make any 8. She didn't want the hair thief to hear her. Then she began carefully 9 her father's head. When she arrived at her father's side, she began looking at his head,10to catch the hair thief as soon as he appeared. Before long, she saw a shadow on it and 11 all her strength, she swung the hammer down.

    Thwack! Her father 12a loud cry. The lump(肿块) on his head was big and growing.13 with shock, he turned the light on and saw Alice waving her hammer in the 14 with her hands. “Daddy, I 15 got him. I thought I 16 him, but it looks like he escaped!” said Alice. At the same time, the mother woke up. She 17laughing when she knew what had happened.

    So Alice's father had to 18to her that the hair thief didn't exist, and that losing hair is something that just happens 19 to most daddies. And Alice still worried about her daddy, but she no longer waited for the hair thief.20 , she bought her daddy a very nice sleeping hat.

①植物细胞细胞液中的有机酸会溶解膜结构；

②光学显微镜下观察，植物细胞看不到细胞膜；

③植物细胞的细胞膜较薄；

④植物细胞有细胞壁，提取细胞膜的过程比较繁琐；

⑤植物细胞内会有其他膜结构干扰．