With Halloween approaching, there exists a real concern among parents and teachers __________ trick or treating will become a seriously anti-social activity.

A．whether

B．what

C．that

D．how

男性，18岁，因溺水入院第3天出现呼吸困难，R40次/分，HR100次/分，BP90/68mmHg.口唇发绀，两肺湿啰音，吸氧5L/min时PaO56mmHg，PaCO28mmHg。患者最可能出现什么并发症()

A．心力衰竭

B．急性呼吸窘迫综合征

C．脑膜炎

D．麻痹性肠梗阻

E．消化道出血