He devoted all his life to ________ those who are suffering from cancer.

When she came back home from school, she found her goldfish _______ on the floor.

I told your friend how to get to the hotel， but I perhaps I __________ have driven her there.

He needs to work ________ hour ________ night.

My father’s new cellphone can be used ______e-mails.— Is he used _____ on such a small screen