Sentence Correction

1. Many teenagers undergo stress, but results of a recent study indicate (that the patterns of stress that girls experience are more likely to result in depression than are those that boys experience.)

2. A study published in the British Medical Journal showed (that women who ate nuts more than five times a week were about one third less likely to suffer from coronary heart disease than were those who ate no nuts at all.)
OA is E
(D)than women eating
(E)than were those who ate

3.Results of a United States study published in the Annals of Internal Medicine have shown (that college-educated women and women living in the South and West are significantly more likely to use supplemental hormones than women living in the Northeast and Midwest.)
why "are" is not needed after "than" in Q3

thank you
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