GC中不正常的色谱峰有
A．对称峰
B．前延峰
C．肩峰
D．拖尾峰
E．对称型正态分布曲线峰
参考答案：B,D
—Excuse me. Could you tell me ________?
— Sorry, I am new here.
A．where the hospital is
B．where is the hospital
C．where the hospital was
D．where was the hospital
有关接电话礼仪的四个基本原则是什么？
