1.  I had thought she must come from the south of Yangtze River.

2.  I don't think men and women should play different roles in life.

3.  Some people may think that college students falling in love will have bad effect in learning.

4.  I don't think we even have to emphasize on the quality of our new product or how elaborate, how exquisite it is because those have always been our advantages from which our reliability comes.

5.  They had thought they would never get married because they are too old.

6.  I don't think that beauty contest should be approved.

7.  I don't think it is necessary to translate and memorize long lists of test words.

8.  I don't think we can memorize the lists consecutively, but we can really do this by reading books and materials.

9.  I may think that the work is done with no effect.

10.  We can think that learning is required , love is optional.