He, a Nobelist, made great ______________ to researching in this area.

At the class meeting the students discussed three different _______ to the study of English.

---- Water can dissolve almost anything and give nutrients to creatures. ---- Yes, and that’s one of its __________.

 Giving children pocket money as a gift during the Spring Festival is a common ____ in     China.

I have to reschedule the appointment with you since there is a ______ in my arrangement.