Nelson Mandela devoted all his life to the struggle of the African people and      of every nation that seeks freedom．

 In the first book, Lyra’s scientist father makes ______ possible to enter other worlds.

 I found _________ hard to make myself understood by the old man.

—I'm too busy preparing the exam. Could you do _______to help me?—Of course. I can do _______for you if you want me to.

—Which of these two sports sweaters will you take? —I’ll take            . I will choose another one.