胰腺癌的肿瘤标志是()
A．CEA
B．AFP
C．CA19-9
D．酸性磷酸酶
E．碱性磷酸酶
参考答案：C
在高速公路上行驶感觉疲劳时，应立即停车休息。
is strange that he didn't come at all. [ ]
A. That
B. This
C. It
