Students can easily fall behind in their studies ____ they don’t manage their spare time carefully.

A．though

B．if

C．since

D．until

男性，42岁，饱餐后上腹部剧痛6小时，伴恶心呕吐，呕吐物为胃内容物，吐后腹痛更加剧，如刀割样。查体：体温37.8℃，脉搏 124/ min，血压80/50mmHg，痛苦面容，腹胀，全腹肌紧张，压痛及反跳痛，上腹部为重，肠鸣音消失，肝浊音区存在，右下腹穿刺得淡红色血性液体，白细胞12×10⁹/L，血淀粉酶 320温氏单位，血钙1.5mmol/L，诊断应考虑

A．溃疡病穿孔，弥漫性腹膜炎

B．胆囊穿孔，弥漫性腹膜炎

C．急性胃炎

D．急性出血性坏死性胰腺炎

E．急性绞窄性肠梗阻