23.0g金属钠投入到足量的重水中,则产生的气体中含有[ ]
A.0.5mol中子
B.1.0NA电子
C.0.5mol质子
D.0.5NA原子
答案:B
We haven't heard from her for weeks. How do you suppose _____ with her studies now? [ ]
A. is she getting along
B. she gets along
C. she is getting on
D. she had got on
类风湿性关节炎的X线表现为
A.良性骨肿瘤B.恶性骨肿瘤C.有恶性倾向的良性骨肿瘤D.骨瘤样病变E.继发性骨肿瘤