From the ________ shown in the dead body, he ________to death by a certain poisonous chemical, but I can’t tell exactly which. [ ]

A. symptoms; must have been poisoned    

B. signs; should have been poisoned

C. symbols; could have been poisoned      

D. appearances; may have been poisoned

预防便秘的措施下列不正确的是()

A．生活有规律，按时排便

B．定时使用缓泻剂

C．多食用粗粮、蔬菜

D．进行增强腹肌的运动

E．餐前提供柠檬汁等热饮料