11. Being ill, I went to my friend who works as a doctor for a ________ (药方).
12. Hundreds of ________（被盗的）bicycles were returned to their owners last month.
13.I can't tell one from the other because they are only ________（细微）different.
14. Thank you for _________ (提供) to help, but I can manage it myself.
15. The words in the _________ (字母表) are what you must learn by heart.
