CAS-OB中OB是指（）。
A.加热
B.加铝
C.吹氧
参考答案：C
—“Dear Frank, when will our wedding be?”
—“Ah, when? God knows.” He said, and ____ away from her, walked rapidly away.
A．turning
B．turned
C．turn
D．to turn
钢制压力容器进行磁粉或者渗透检测，合格级别为（）级。
A.Ⅰ
B.Ⅱ
C.Ⅲ
