单项选择题 There are at least a dozen inflectional affixes. ( )

单项选择题 精清中的蛋白质含量很低,一般为( ) A. 1%-2% B. 2%-5% C. 3%-7% D. 7%-10%

多项选择题 What are the principles that a concierge should follow? A、Serve guests heart and soul. B、Be friendly to guests. C、Be passionate to guests. D、Neglect the guest's demand.