22岁女医学生，课间实习观看外科手术，站立3小时，突然头晕、恶心、眼前发黑、意识丧失
题型：单项选择题
问题：
22岁女医学生，课间实习观看外科手术，站立3小时，突然头晕、恶心、眼前发黑、意识丧失、跌倒，四肢强直，伴面色苍白、出汗，约持续10秒种后意识清醒。神经系统查体未见阳性体征。血糖化验为4mmol／L，头MRI检查未见异常。最可能的诊断（）
A.假性癫痫发作
B.强直性发作
C.低血糖症
D.晕厥
E.椎-基动脉供血不足
题型：单项选择题
His efforts to raise money for his program were ______ because, no one showed any intention to take a cent out of their pockets.
A．in place
B．in sight
C．in effect
D．in vain