题干
All witnesses _____ to the traffic accident are required to make their statements.
A：appropriate
B：accessible
C：relevant
D：suitable
答案(点此获取答案解析）
C
A：appropriate
B：accessible
C：relevant
D：suitable
CH3COO-＋H+已达平衡，若要使醋酸的电离平衡向左移动和溶液的pH值都减小，应加入的试剂是