单项选择题
Coffee has been a favorite drink for centuries，_______the time when we were drinking it strong and black，without sugar.
单项选择题 You______ engage in serious debate or discussion unless you are willing to endure attacks.
单项选择题 This video may be freely reproduced _______ commercial promotion or sale.
单项选择题 He added that the state government has made _______ arrangements for the conference.
