中俄贸易存在的主要问题有( )
A.贸易规模较小
B.进出口商品结构层次不高
C.贸易经营主体层次低
D.投资对贸易拉动效果较差
E.缺乏良好的贸易秩序
参考答案:A,B,C,D,E
An artist who was recently traveling on a ferry to the southern island discovered ________ a long lost antique Greek vase.
A.at random
B.by chance
C.in turn
D.on occasion
血清无机磷正常值为
A.0.70~1.10mmol/LB.0.96~1.62mmol/LC.290~310mmol/LD.7.35~7.45E.2.25—2.75mmol/L