China Mobile has to face the problem that more and more people in China prefer to choose ______ cheaper wireless phone service known as ______ “Little Smart”.

A．a; the

B．a; 不填

C．the; 不填

D．the; the

常发生钙化的颅内肿瘤有（）

A．少突胶质细胞瘤

B．听神经瘤

C．颅咽管瘤

D．血管网状细胞瘤

E．脑膜瘤