.

_________ it was to become was a mystery until the dust began to slowly combine into a ball moving around the sun.

A．That

B．What

C．Which

D．Whether

男，68岁，患“胃炎”20余年，因突然出现全腹剧烈疼痛，病人被动屈曲位，初体温正常，后出现最高体温38.5℃，脉搏110次/分，查体：腹式呼吸减弱，腹肌紧张不明显，全腹压痛、反跳痛，以上腹部为重；X线立位平片示小肠普遍胀气，并见小液气平面，膈下见游离气体。

根据上述症状及体征，最可能诊断为()

A．胃出血

B．胃穿孔

C．肠梗阻

D．急性胃肠炎

E．胆绞痛