A. happy couples try their best to maintain their good relationship
B. happy couples can enjoy their marriage for their whole life
C. unhappy couples take their relationship for granted
D. unhappy couples just want to separate from each other
A. how to be kind to others
B. how to get along with others
C. how to save one's marriage
D. how to live happily
A. lower cost
B. more convenience
C. fewer side effects
D. more effectiveness
A. fewer injections
B. immediate symptoms
C. longer effective periods
D. different injection methods