What worried the child most was to visit his mother in the hospital.A. his not allowingB

问题补充：

What worried the child most was to visit his mother in the hospital.

A. his not allowing

B. his not being allowed

C. his being not allowed

D. having not been allowed

答案：

A. his not allowing

(答案→)B. his not being allowed

C. his being not allowed

D. having not been allowed

解析：考查动名词的复合结构。动名词的原形是doing，被动式为being done，否定式是在前面直接加not，复合结构是在not前面加所有格或者宾格。句意：让这个孩子担忧的事情是他不被允许到医院看妈妈。故B正确。