鸟氨酸脱羧生成
A．多巴胺B．腐胺C．酪胺D．尸胺
参考答案：B
He's been told to _____ the next month's meeting. [ ]
A. be present
B. be present at
C. present
D. be present in
在ILSC（音降）中，指点标上将观测到什么样的听觉和目视指示？
