分子的平均平动动能,分子的平均动能,分子的平均能量,在一定温度时有如下关系()。
A.三者一定相等
B.前二者相等
C.后两者相等
D.对单原子理想气体三者相等
参考答案:D
若a<b+3,且b+3<2c,则a______2c.理由是______.
____ the end of last year, I have been working on the project, and it is progressing well. [ ]
A. Since
B. By
C. At
D. In