熟地、当归属()
A. 补阴药
B. 补阳药
C. 补气药
D. 补血药
Two-thirds of his property_____lost in the fire.
A. was
B. were
C. are
D. have been
William has cut his smoking_____to five cigarettes a day.
A. down
B. short
C. away
D. off
在关系数据库中,用来表示实体问联系的是()
A. 属性
B. 二维表
C. 网状结构
D. 树状结构