正常人的CD4+／CD8+T细胞的比值为（）。
A.0.5～1.0
B.≤1.0
C.1.4～2.0
D.≥3.0
E.≥5.0
参考答案：C
It is generally believed that teaching is _____ it is a science.
A．an art much as
B．much an art as
C．as an art much as
D．as much an art as
长期失眠（）
A．进行性多灶性白质脑病
B．进行性风疹性全脑炎
C．亚急性硬化性全脑炎
D．Gerstmann-Straussler-Scheinker综合征
E．单纯疱疹病毒性脑炎
