11.  A pair of.

12.  A quite awful vase in one corner, full of dried pampas grass.

13.  A., all strangers to me, beloved by her but oddly never spoken of.

14.  According to the standard seventeenth-century view, there exist, independently of and antecedently to our perception of them, material bodies.

15.  Accordingly, proper legal advice should be taken to ensure all protection available is actually taken advantage of.

16.  After a year he had enrolled at City College, which he had learned of through a cousin who was attending.

17.  All teachers have children that they are particularly fond of.

18.  All the stuff he said about spiders kind of scared me.

19.  All unpleasant, especially to a small child, but usually of brief duration and causing no lasting damage.