THDS-A红外轴温探测系统中，热靶大门组合件为（）提供温度基准。
A.轴温计算
B.热靶标定
C.系统标定
D.探头标定
参考答案：A
My sister was afraid out at night, because she was afraid____ the dogs. [ ]
A. of going; to
B. to go; of
C. going; of
D. to go; to
根尖周炎的主要病因是
A．免疫因素B．物理因素C．化学因素D．感染因素E．特发因素
