He always dreams of ______ a chance for him to go abroad for further study．

A．there being

B．there to be

C．there is

D．being

以下哪项不是SPF级大鼠病毒检测必须检测项目？（）

A.汉坦病毒

B.鼠痘病毒

C.仙台病毒

D.小鼠肺炎病毒