腹部可有痛性包块伴休克的是（）
A.蛔虫性肠梗阻
B.麻痹性肠梗阻
C.绞窄性肠梗阻
D.单纯性肠梗阻
E.血运性肠梗阻
参考答案：C
血气分析仪的电极维护保养主要有（）
A.参比电极保养
B.pH电极保养
C.PCO2电极保养
D.PO2电极保养
E.铂电极保养
Nongfu Spring, one of China’s biggest bottled water companies, was reported ________ to meet national standards, and its chairman held a news conference in Beijing on May 7.
A．having failed
B．to fail
C．failing
D．to have failed
