Speaking of all the songs he has written, I think this is probably his __________ one

May I have a dog at home, Mum—Yes, you can. But you must know how to _________ it.

Extra boiling water should be kept at hand just ______ it is needed.

The new movie_____to be one of the biggest money-makers of all time .[ ]

Do you need any help, Lucy?—Yes, The job is _____1 could do myself.[ ]