The hard, out surface of the tooth is called enamel.

A．outside

B．appearance

C．outer

D．hiding

脑出血病人出现下列哪些情况提示有脑疝的可能（）

A.意识障碍加重

B.呕吐频繁

C.血压升高

D.心率变慢

E.烦躁不安