题干
Though the runner fell, _______ he quickly got up and went on running.
A：or
B：but
C：／
D：so
答案(点此获取答案解析）
C
pC(g)，达到平衡后，保持温度不变，将气体体积缩小到原来的一半，当达到新平衡时，C的浓度为原来1.9倍，下列说法错误的是