为病人做药物过敏试验时，最重要的准备工作是()
A．询问病人有无过敏史
B．物品齐全
C．剂量准确
D．环境要清洁
E．选择合适的注射部位
参考答案：A
真核rRNA的转录后加工（）
A．切除部分肽链
B．3’末端加-CCA
C．3’未端加polyA
D．45SrRNA的剪切
E．亚单位的聚合
— What about your journey to Mount Hua?
— Everything was wonderful except that the car we rented________on the way back. [ ]
A. broke up
B. broke down
C. broke out
D. broke in
