唾液维持口腔pH是由于唾液中含有()。
A.淀粉酶
B.黏蛋白
C.大量的可产酸的细菌
D.免疫球蛋白
E.如重碳酸盐缓冲系的多种缓冲体系的存在
参考答案:E
______ was the situation we were facing .
A.So
B.Such
C.What
D.It
At that time, the movie “Shaolin Temple”, _________Li Lianjie plays the starring role, drew the world’s attention to Chinese Kungfu.
A.where
B.when
C.that
D.which