Choose the word (A, B, C or D) that best completes the sentence

Choose the word (A, B, C or D) that best completes the sentence: Peter won’t get used to _______ the night shift. He needs his sleep. *
A. work
B. worked
C. working
D. to work
Choose the word (A, B, C or D) that best completes the sentence: I strongly suggest _______ personal and business account separate. *
A. keeping
B. to keep
C. kept
D. keeps
Choose the word (A, B, C or D) that best completes the sentence: She _____ the English Channel every summer until 1997. *
A. swims
B. had swum
C. swam
D. has swum