1£¬  How do you learn English grammar?

 _ I study _____ learning English stories.

  A. to      B. by    C. on   D. in

2, I don’t know the word ,I want to _____ in the dictionary.

  A. look up it   B. find it    C. look it up   D. find it out

3, Have you decided which sweater_______?

  A. choose    B. choosing    C. chosen  D. to choose

4, You are in poor health ,You should give up _____.

  A. to smoke  B. to smoking  C. smoke  D. smoking

5, Knowing a lot of languages ______ him to make many friends across the world.

  A. helps      B. help     C. to help  D. helping