4．表示重要、必要、困难、方便、可能
        1）It is important（necessary，difficult，convenient，
        possible）for sb．to do sth．
        2）We think it necessary to do sth．
        3）It plays an important role in our life．
        　　　　
        例如：
        Computers are now being used everywhere，whether in the
        government，in schools or in business．Soon， computers will be found in every home，too．We have good reason to say that
        computers are playing an increasingly important role in our
        life and we have stepped into the Computer Age．
        　　　　
        5．表示措施
        1）We should take some effective measures．
        2）We should try our best to overcome（conquer）the
        difficulties．
        3）We should do our utmost in doing sth．
        4）We should solve the problems that we are
        confronted（faced）with．
        
        例如：
        The housing problem that we are confronted with is
        becoming more and more serious．Therefore，we must take some
        effective measures to solve it．
        　　　　
        6．表示变化
        1）Some changes have taken place in the past five years．
        2）A great change will certainly be produced in the world’s
        communications．
        3）The computer has brought about many changes in
        education．
        　　　　
        例如：
        Some changes have taken place in people’s diet in the past
        five years．The major reasons for these changes are not far to seek．Nowadays，more and more people are switching from grain to meat for protein，and from fruit and vegetable to milk for vitamins．
        7．表示事实、现状
        1）We cannot ignore the fact that．．．
        2）No one can deny the fact that．．．
        3）There is no denying the fact that．．．
        4）This is a phenomenon that many people are interested in．
        5）However，that’s not the case．
        例如：
        We cannot ignore the fact that industrialization brings
        with it the problems of pollution．To solve these problems， we can start by educating the public about the hazards of
        pollution．The government on its part should also design
        stricter laws to promote a cleaner environment．
        　　　　
        8．表示比较
        1）Compared with A，B．．．
        2）I prefer to read rather than watch TV．
        3）There is a striking contrast between them．
        　　　　
        例如：
        Compared with cars，bicycles have several advantages
        besides being affordable．Firstly，they do not consume natural
        resources of petroleum．Secondly，they do not cause the
        pollution problem．Last but not least，they contribute to
        people’s health by giving them due physical exercise．
        　　　　
        9．表示数量
        1）It has increased（decreased）from．．．to．．．
        2）The population in this city has now increased
        （decreased）to 800，000．
        3）The output of July in this factory increased by 15％
        compared with that of January．