_______ on rescuing her sick son, the poor mother has been working 16 hours a day.
Nowadays,few people form the habit of keeping a supply of candles in the house in case of power ________.
—Could you tell me the way to ________ Johnsons,please?—Sorry,we don't have ________ Johnson here in the village.
________ material used for running tracks in schools across China may be ________ danger to children's health.
I sent a big bunch of flowers to the nurse as an ________ of thanks for her taking good care of my grandpa in the nursing home.
If you don't work hard,it will be of no ________ for others to help you.