56. Miss Lee often ( write ) . . . . . wrote. . . .. . . . when she was on holiday.

57. Tom ( study ) . . . . . .studied . . .. . . . chemistry for 3 years and then he gave it up.

58. My brother ( join ) . . . . . joined. . . .. . . . the army when he ( be ) . . was. . . . . . .. . . . young

59. have You ( receive ) . . . . received. . . . .. . . . any letters from your parents yet?

60. How long have Bob and Mary ( be ) . . . . been. . . . .. . . . married?