A:专利性
B:创新性
C:综合性
D:两面性
____ is the last month of the year.
—Which would you like, tea or coffee?
—Either _______ OK, but I prefer coffee _______ tea.
氮化钠(Na3N)是科学家制备的一种重要化合物,它与水作用可产生NH3,请回答: