31.  He started a new political idea call "communism".

32.  After a while, I had an idea.

33.  I can't write my words to express my idea.

34.  But when the winter holiday came really, I found my idea was impossible.

35.  We can talk about the experience and ideas of the study with each other.

36.  He only asked and collected our ideas, and he didn't order us to do anything.

37.  Scientists try to find ideas to do with the gases .

38.  Because they sometimes have different ideas .

39.  It is a common idea for our study among students.

40.  In everyday life, most of people know an idea that is "Practice Makes Perfect".