男性，66岁，原有冠心病史10年，平素无症状，近日常清晨发作胸痛，持续时间20～30分钟。胸痛发作时心电图V～V、T波直立，缓解后T波倒置。此时诊断应考虑（）

A.劳力型心绞痛

B.卧位型心绞痛

C.变异型心绞痛

D.心内膜下心肌梗死

E.梗塞后心绞痛

A vessel is tender if cargo weight is（）.

A.concentrated high and the double bottoms empty

B.concentrated low and the double bottoms empty

C.evenly distributed vertically with the double bottoms full

D.concentrated and with the double bottoms full