28. Vitamin D helps our bodies make a special chemical, and this special chemical, _______, affects our brains, making us feel happy.
I’m afraid taking a part—time job might ____ my time for study.
Was it not until you began to work ___ how much time you had wasted?
The city ________ against the terrible possibility of such things happening again.
.I’m sorry, but I didn’t mean to be rude to you. Can you______ me?
—Have you heard the story of “The Merchant of Venice”? —No. When and where does the story ______ ?