Smoking is one of the ______ causes of cancer, killing millions of people each year.[ ]

The boy felt quite happy becausehe was closer now to ______ an answer of his own.

How is your grandma—She’s fine. She used to______ TV at home after supper. But now she is used to going out for a walk.

I looked everywhere in the house ______ a key that had been lost

Thefreezingpointisthetemperature__________waterchangesintoice.