Reading this instructive book, ___________ .
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 being allowed
What we have said ________ her so happy.
What have we said _______ her so happy?
Having a trip abroad is certainly good for the old couple, but it remains _______ whether they will enjoy it.
The picture _______ on the wall is painted by my nephew.