He looked around and caught a man _______ his hand into the pocket of a passenger.

A．put

B．to be putting

C．to put

D．putting

男性，40岁。胸痛、反酸、胃灼热、嗳气2个月，胃镜检查食管粘膜未见明显异常，最有助于明确诊断的检查是（）

A.上消化道气钡双重造影

B.¹³C尿素呼气试验

C.24h胃食管pH监测

D.腹部B超

E.24h心电监测