Some researchers are finding that daydreaming may be important to     mental health .Daydreaming ,they say, is      good means of relaxation.

A．the; ／

B．／; the

C．／; ／

D．／; a

患者，女性，37岁。反复出现右上腹绞痛，伴发热，黄疸半年余。为明确诊断，应首先采用的检查是

A．B超
B．胆囊或胆道造影
C．磁共振成像
D．口服胆囊造影
E．纤维胆道镜