15. After retiring, he was recommended to ____ gardening as a hobby.
._____ alone in the large house, the little boy had to learn to survive by himself.
Chengdu is a city _______ you hate to say goodbye once you have visited it.
— Did you see a man in black pass by just now? — No, sir. I _______ a newspaper.
My parents don’t care _______ my pocket money goes, but one thing is for sure: the money spent must be worthwhile.
—Why didn’t you go to Mike’s birthday party yesterday? —Well, I _______, but I forgot it.