阅读材料，回答问题：

材料一：1956年元旦，北京市各行各业工商业者申请实行全行业公私合营，得到北京市人民政府批准。1月15日，20万人敲锣打鼓上街游行，庆祝实现全行业公私合营。紧接着，天津、上海也先后实现了全行业公私合营。1月底，全国所有大城市和50多个中等城市的资本主义工商业者都实行了全行业公私合营。

材料二：

方方从家到图书馆，用了30分钟，她平均每分钟走 $\frac{1}{3}$ 千米，她家距离图书馆有多少千米？

菜粉蝶是一种危害十字花科蔬菜的害虫，下图是它发育过程中四个时期的形态图，请据图回答问题：

① ② ③  ④

    Happiness means different things to different people. For Mary, who has ____ severe sleeping problem, happiness is as simple as having a good night's sleep.

    Bed was once a place ____ Mary went to rest after a long, hard day. ____, she has not had a full night's sleep in almost six months. Her doctor said that____(count) sheep might help her fall asleep. She tried this, but soon got tired of it after it failed to work. She finds the nights without sleep almost ____(bear) . She is always sleepy and lacks energy during the day.

    Mary is not alone. Studies show that more than one in three people worldwide struggle with getting enough sleep. It often takes on different ____(form) : some people can get to sleep, but wake up much too early; some get a full night's sleep, but are ____(disappoint)  to find that they still feel tired when they wake up; others, like Mary, find ____ difficult to fall asleep in the first place.

    Specialists say that people should not worry too much about this problem. In most cases, a lack of sleep ____(cause) by anxiety and pressure. It is important to keep yourself ____ good spirits and to be positive.