— Where were you just now?
— I _____________ in the playground.[ ]
A. were
B. was
C. am
答案:B
皮肌炎患者中女性、男性之比为()。
A.2:1
B.4:1
C.7:1
D.9:1
E.3:1
从活动水平的角度看,个体实践活动体系中第一层次的活动是( )。
A.课堂活动 B.心理活动 C.社会活动 D.生理活动