电控变色后视镜提供的人所感觉舒服的反射率为（）
A.15%-25%
B.20%-30%
C.25%-35%
D.30%-40%
参考答案：B
With so many forms ___, many students feel at a loss before the 2012 college entrance exam.[ ]
A. filling in
B. filled in
C. to fill in
D. to be filled in
怎样诊断高血压？高血压分级标准是什么？
